Abstracts of the 13th Annual Meeting of Israel Society for Neuroscience

s of the 13th Annual Meeting of Israel Society for Neuroscience Eilat, Israel, November 28-30, 2004 Motor control of regenerated arm ofthe octopus Adam R.’, Sumbre G.’, Flash T.3, Hochner B. and Yekutieli ’Dept. ofNeurobiol_oy, Hebrew Universit, Jerusale_my; InterdiJciplinary Cnterfor Neural Computa#on, Hebrew University ofJ_e:rusalem; 3Computer Science andApplied Mathematics, Weizmann Institute ofScience, Rehovot The octopus arm lacks agy rigid skeleton and has virtually .an_ intimte n.u.mb"er of degrees of freedom (.DOFs): .Movements oI the octopus arm are studied to understand the motor control of this hyper-redundant system. Previous studies showed that the octopus uses stereotypic reaching move.me_n.ts which .reduce the nqm.be.r of.control parameters to qnly 3 _(,on.e tor tte velocity 9tthe tend point propagation ancl two tor the orientation oI.the proximalpart oithe ._art0), We compar&l movements ot a regenerative arm (half the size of normal arms) to those of normal arms in simultaneous reachine movements (both arms reach at the same time, SMs) and" individual reaching movements (.the arms reach independently, IMs). For IM_s, the distance th.at the bend .point moved and the time or movement tor the regenerative arm was half of those of the normal arms. The t.angential velocity profiles had a stereotvlic bell shape car.acterizatio.n...St.mu!ati.gns of I.Ms b.y adynamc, model ot the arms. yielded similar results (t command was a constant velocity wave of muscle activation that took half the time to travel along the am for the smaller arm)..In qgntrast to. IMs, no sigrp,ficant differences were found in the_ distance that the bend point moved and in the time oi reaching between the regenerative arm to the normal arms in SMs. The time and the distance of the reaching movements of the regenerative arm were significantly larger in SMs than in IMs. The standard deviatmn of the maximal velocity of both arm .types vas smaller in .the S.Ms than in the IMs. Tangential velocity.profiles didn’t hav.e the bell sh.ape characterization in SMs. Qur.hypothesis is that.in SMs there is one motor command that coordinates the muscle activation wave which propels the bend. Supported by DARPA and ISl,’grants. Peptide Nucleic Acid (PNA) based antisence molecules for treatment of CNS disorders. ’, Koverigin I., Bornstein R.:, Katzhendler Y.. and Lamensdorf I.’ ’Dept. ofNeurology Hadassah Universi Hospital Jerusalem; PharmaSense Ltd Pakris 4 St. Rabin science Park, Rehovot; Dept. ofMedicinal Chemistry., Pharmacy School, Hebrew Uhiversity, Jerusalem; Recent advances in neuroscience have led an increasing number of gene targets for treatment of brain tumors ar degenerative CNS diseases. A new and promising therapeutic approach has evolved based on antisense molecules. These are small strands of DNA (oligodeoxynucleotides, ODN) designed to bind to an mRNA tgget, thus inhibiting transcription of encoded protein. The advantage of antisence based treatment is higher selectivity towards a desired target. Polyamide (peptide) nucleic acids (PNA) are the third generation of antlsense chemistry. They represent a novel concept as th_ey have improved nucleic aciit properties and peptide-li.ki chemistry, enabling implantation oI-peptide biology into the nucleic acid field. Recent studies suggest that PNA cross the BBB and are internalized into neurons. PNA uptake properties were studied in vitro and in vivo in endothelial, gial and neuronal models. I.n primary tissue culture models e could demonstrate selective uptake of PNA into neuronal, glial and endothelial cells: FACS sorting analysis of fluorescence labeled PNA uptake into NMB, C6 and ENDB3 cell lines (models t’or neuronal, glial and endothelial components, respectively) showed uptake of PNA by neuronal cells but not by glial or endothelial cells. Intracellular PNA uptake into NMB cells was fo.und to be temperature sensitive. In low concentration there is a maked difference between uptake into neuronal cells as compared.to uptake into glial and endothelial cells this may suggest the Oxistenee of a transport mechanism. PNA intracellular accumulation has a punctuated pattern, an indic.ation of endosomal/lysosomaI trapping. Long term incubation of cells with high concentration ofPNA was no ac.companied by cellular to,city. Following direct. admimstration ofPNAs into the brain we show selective uptake of PNAs into neuronal cells. No signs of cellular toxicity could be demonstrated as opposed to other ODN that are known to be toxic in high concentration. ATP dependence ofthe non specific ion channel in Torpedo synaptic vesicles Ahdut-Hacohen IL, Levy T., Abu-Hatoum T., Meiri H. and Rahamimoff R. _Dept. ofPhysiolog & B.KatzMinerva Centre. Hebrew UniversityMedichl School, Jerusalem; SynapOc vesicles, of Torpedo electromotor neurons contain, .adaition to me neurotransmitter acetyleholi_ne, also a .high concentration of ATP. The coneentrion ortotal ATP s around 120 mM while the free [ATP] is about 5-6 m.M, We examined the ’effect of the ATP concentration on the opening of the non-specific ion channel in Torpedo .synaltle vesicle membrane. We found that the non-specific ion channel is closed when the ATP concentration is 0. 30 10 and 5 mM_ but it ons very frequ.nt.ly at’ conc.entrations of l and 0 inM ATP. The single channel conductance di.d not change signi0cantty with ATP concentration. W.e assert that_these.results hnv.e significant,e in two_ different directions. irst, they may take part in me. post Iusion control of transmitter release. Ulx/fusion ot ihe vesicle with the surface membrane, the ATP leaks from the vesicle to the extracetlular medium and thus the probabili.ty ofthe .opening ofthe non-specific ion channel is m.crease which iai turn may lead to mn exchange and to release or trans.mitte3".. The second possible c.o0seque.nge of_ .these results is that during metabohc stress and reduction ot e inNavesieular ATP. eg.ncentration, the non-specific ipn ctmnne can open ana aissipate the ion_.gradiepts in t vesicle, membrane. This in turn may. Ntet sutstantially transrmtter release and synaptic transmissmn. GABAA agonist facilitates extinction of conditioned fear in the infralimbic prefrontal cortex and the basolateral amygdala Akirav I.’, Reizel H., Dudai y.x and Maroun M. "Dep{Ofleurobiolog’, Weizmann Institute ofScience, Rehovot 7 e6100l; ’Tile Brain and Behavior Research Center, Univers#y ofHaifa, Haifa 31905; In fear conditioning, repeated presentation of the tone in the absence of the shocl causes previously acquired fear responses 9 gr’4dually decline. Most studies examined ex-perimental extinction processes in either the infralimbic prefrontal cortex (IL) or the basolateral nmygdala (BLA), both implicated in extinction of fear. Here, we focused on the kinetics of fear extinction in both structtwes, while using the same paradigm and temporal parameters of drug infusion. Hence, we mieroinfused the -aminobutyri acid (GABA)A aggnist muscimol into the IL or BLA to examine its effect on the extinction of fear conditioning. Museim.ol infused to IL before extinction training (but not after eitlaer shortor long extinction training), resulted in long-term facilitation of-extinction. Infusion of muscimol to the BLA, following a short training session, transiently facilitated_ extinction. The differences in the temporal parameters of the effects of museimol in the IL or BLA, suggest differential involvement of these structures in lo0.gz-term extinction of fear memory. We propose that consotiation of extinction of fear may .dependent on both the amgd.ala and I..L and concurrently the information is. turter consolilated and stored m the IL. Understanding the interaction between the amygdala and the prefrontal cortex in extinction of fearful experiences is of major interest, since these brain .regions are closely related to the persistence of mala_dalStive fear seen in anxie disorders such as post-traumatic stress disorder (PTSD) and phobia. Bifunctionai compounds eliciting non-steroidal anti inflammatory and cholinergic up-regulation as treatment for CNS inflammation Amitai G., Nizri E.2, Adani R., Meshulam H." and 1Division ofMedicinal Chemis___, I1BR, Ness Ziona; 2Lab. ofNeuroimrnunology, Dept. ofNeurol.ogy, Hadassah Hebrew UniversitbrMedical Center, Jerusalem; It was previously noted that vagus nerve activation could .suppress significantly the release of maerpp_hage promtlammatory a,ents attenuating systemic irttlammat..ory presses. This cholineygic anti-mfiammat_0ry pathway" is mediated by the alpha7 nicotinic ACh receptor in macr0phages. Therefore, we examined the in rive antineuroibammatory effica., of bifunctional compounds containing the NSAID ibup_rofen (IBU) or dielofenae (DICLO) and a ChE inhibitor Pyridostigmine QcI (PO) or Decyl (PD). IBU-PO caused a significant reduction in rat paw and brain edema induced by earrageenan. IBU-PO, IBU-PD reduced signific.antly_ the soman-induced (1.2LD50) brain edema in mice. Pre-treatment with IBUPO, IBU-PD, or DICLO-PD 4-5 hours before soman challenge (2.2-2.3 LD50) combined with antidotal treatment (atropine and 2-PAM-CI), afforded higher survival rate than with PYIL DICLO-PD displayed 70% survival at 24h compared to 17% with PYR. IBU-PO and IBU-PD were examined in experimental autoimmune encephalomyelitis (EAE), a model used for _.s3udying human Multiple Sclerosis. These compounds ameliorated.by 4050% the neurological score (l and 0.1mg/kg, ip, respectively). T ceils derived from IBU-PO-treated EAE animals displayed decreased reactivity in response to the .myelin oligodendrocyte glycoprot_ein (MEG) and also to tlae mitogcn PHA, indicating reduced activity of MeGspecifi Tcells. In addition,-IBU-PO at micromolar levels down regulated LPS-indueed nitric oxide (NO) and PGE2 production in rat brain astrocytes. T-cell proliferation, NO hnd PGE2 production in astro.cytes was m’.d_dly inhibited by_ IBU and none by PO alone, bit was significantly reduced 

(peptide) nucleic acids (PNA) are the third generation of antlsense chemistry. They represent a novel concept as th_ey have improved nucleic aciit properties and peptide-li.ki chemistry, enabling implantation oI-peptide biology into the nucleic acid field. Recent studies suggest that PNA cross the BBB and are internalized into neurons. PNA uptake properties were studied in vitro and in vivo in endothelial, gial and neuronal models. I.n primary tissue culture models e could demonstrate selective uptake of PNA into neuronal, glial and endothelial cells: FACS sorting analysis of fluorescence labeled PNA uptake into NMB, C6 and ENDB3 cell lines (models t'or neuronal, glial and endothelial components, respectively) showed uptake of PNA by neuronal cells but not by glial or endothelial cells. Intracellular PNA uptake into NMB cells was fo.und to be temperature sensitive. In low concentration there is a maked difference between uptake into neuronal cells as compared.to uptake into glial and endothelial cells this may suggest the Oxistenee of a transport mechanism. PNA intracellular accumulation has a punctuated pattern, an indic.ation of endosomal/lysosomaI trapping. Long term incubation of cells with high concentration ofPNA was no ac.companied by cellular to, city. Following direct. admimstration of PNAs into the brain we show selective uptake of PNAs into neuronal cells. No signs of cellular toxicity could be demonstrated as opposed to other ODN that are known to be toxic in high concentration. ATP dependence ofthe non specific ion channel in Torpedo synaptic vesicles Ahdut-Hacohen IL, Levy T., Abu-Hatoum T., Meiri H. .adaition to me neurotransmitter acetyleholi_ne, also a .high concentration of ATP. The coneentrion ortotal ATP s around 120 mM while the free [ATP] is about 5-6 m.M, We examined the 'effect of the ATP concentration on the opening of the non-specific ion channel in Torpedo .synaltle vesicle membrane. We found that the non-specific ion channel is closed when the ATP concentration is 0. 30 10 and 5 mM_ but it ons very frequ.nt.ly at' conc.entrations of l and 0 inM ATP. The single channel conductance di.d not change signi0cantty with ATP concentration. W.e assert that_these.results hnv.e significant,e in two_ different directions. irst, they may take part in me.
post Iusion control of transmitter release. Ulx/fusion ot ihe vesicle with the surface membrane, the ATP leaks from the vesicle to the extracetlular medium and thus the probabili.ty of the .opening ofthe non-specific ion channel is m.crease which iai turn may lead to mn exchange and to release or trans.mitte3".. The second possible c.o0seque.nge of_ .these results is that during metabohc stress and reduction ot e inNavesieular ATP. eg In fear conditioning, repeated presentation of the tone in the absence of the shocl causes previously acquired fear responses 9 gr'4dually decline. Most studies examined ex-perimental extinction processes in either the infralimbic prefrontal cortex (IL) or the basolateral nmygdala (BLA), both implicated in extinction of fear. Here, we focused on the kinetics of fear extinction in both structtwes, while using the same paradigm and temporal parameters of drug infusion. Hence, we mieroinfused the -aminobutyri acid (GABA)A aggnist muscimol into the IL or BLA to examine its effect on the extinction of fear conditioning. Museim. ol infused to IL before extinction training (but not after eitlaer shortor long extinction training), resulted in long-term facilitation of-extinction. Infusion of muscimol to the BLA, following a short training session, transiently facilitated_ extinction. The differences in the temporal parameters of Bifunctionai compounds eliciting non-steroidal anti inflammatory and cholinergic up-regulation as treatment for CNS inflammation Amitai G. , Nizri E. 2, Adani R. , Meshulam H." and 1Division of Medicinal Chemis___, I1BR,Ness Ziona;2Lab. of Neuroimrnunology, Dept. ofNeurol.ogy, Hadassah Hebrew UniversitbrMedical Center, Jerusalem; It was previously noted that vagus nerve activation could .suppress significantly the release of maerpp_hage promtlammatory a,ents attenuating systemic irttlammat..ory presses. This cholineygic anti-mfiammat_0ry pathway" is mediated by the alpha7 nicotinic ACh receptor in macr0phages. Therefore, we examined the in rive antineuroibammatory effica., of bifunctional compounds containing the NSAID ibup_rofen (IBU) or dielofenae (DICLO) and a ChE inhibitor Pyridostigmine QcI (PO) or Decyl (PD). IBU-PO caused a significant reduction in rat paw and brain edema induced by earrageenan. IBU-PO, IBU-PD reduced signific.antly_ the soman-induced (1.2LD50) brain edema in mice. Pre-treatment with IBU-PO, IBU-PD, or DICLO-PD 4-5 hours before soman challenge (2.2-2.3 LD50) combined with antidotal treatment (atropine and 2-PAM-CI), afforded higher survival rate than with PYIL DICLO-PD displayed 70% survival at 24h compared to 17% with PYR. IBU-PO and IBU-PD were examined in experimental autoimmune encephalomyelitis (EAE), a model used for _.s3udying human Multiple Sclerosis. These compounds ameliorated.by 40-50% the neurological score (l and 0.1mg/kg, ip, respectively). T ceils derived from IBU-PO-treated EAE animals displayed decreased reactivity in response to the .myelin oligodendrocyte glycoprot_ein (MEG) and also to tlae mitogcn PHA, indicating reduced activity of MeGspecifi Tcells. In addition,-IBU-PO at micromolar levels down regulated LPS-indueed nitric oxide (NO) and PGE2 production in rat brain astrocytes. T-cell proliferation, NO hnd PGE2 production in astro.cytes was m'.d_dly inhibited by_ IBU and none by PO alone, bit was significantly reduced by IB_U-PO. In addition, human T-cells proliferation w.as sgnilicantly reduced by IBU-Octyl-Cytisme (l-5uM) mat co.ns,ists of" NSAID and a nicotinic aggnist. Our data indicate that molecular combination 6f NSAID with cholinergic up-regulation _may be a novel approach for the treatment of CNS inflammation and .demyelinating disorders.
Clinical and immunological amelioration of chronic experimental autoimmu_ne myasthenia gravis by an-tisense oligonucleotide treatment tav-hamra Y., Sicsic C. and Brenner T. Deptl bf Neurbiogy Hadassah Medical Center, Jerusalem Myasthenia gravis is an antibody-mediated, autoimmune neuromuscular disease in which the nicotinic acetylcholine. receptor (AChR) is the major autoantigen. Th tieal neuromuscular junction symptoms can be transiently alleviated by acetylcholinesterase (ACHE) inhibit.ors (such as pyriaosti_gmine). Previously we found that long-term geatment of experim.ental autoimmune myasthenia s (EAMG) rats with antisonso oligodeoxynueleotides suppr.essing AChE biosynthesis (ENI01), improved muscle activity as well as clinical sympto_m_s of the disease. In the pres .et study We focused on the effect of EN101 treatment on. the typical immunological pr0eesses occurring in EAMG. gpeated oral istfation of EN101 for a month reduced, the anti-rat AChR antibody level by 50/.0. In addition, incubation of T-cells with EN101 rdsulted in reduction in the proliferation rate and induction of apoptosis. EN101 also lowered total IgG antibody production by spleen cells. Our results show he beneficial effect of oral ENI01 trea .t(nent on EAMG immunological parameters and highlight me potential advantage of genetargeted drug therapy. Liga.nd-induced activati_on of G-proteins is differentially regulated by leucine of the CB1 helix 8 domain Anavi_-Goffer S.', Hurst D?, Reggio PH.', Abood ME. ' The majority of physiological actions of marijuana in_the CNS are mediated by activation of G-protein coupled CBI receptors located on neurons. Modeling studies have identified the 404-414 segrnent of CB receptor to be an intracellular helical exter/sion of the TMH7 domain, so called helix8 (HxS) domain. The peptide of CB 401-417 can directly activated Gao/Gai3, but not Gail/2 proteins.
We tested the hypothesis that activation of CBI releases Hx8 such that it can interact with G proteins, and that differences in this association _nmy contribute to constitutive activity. We hothesized that replacing the L7.60 to the bulkier lie residue will make the I-Ix8 more mobile whereas the aromatic Phe will make the Hx8 less mobile than the wild-.type human CB receptor (WT hCB1) thus constitutive acti'bty will be increasdd or decreased, respectively. HEK293 cells were transfected with WT hCB1, L7.60I or L7.60F mutant receptors. Saturation binding analysis with [3H]CP-55,940 and [3H]SRI41617A showed that ligand affini and receptor levels of the mutant receptors were similar to that of the WT hCBI.
[35S]GTPS binding analysis was performed with structurally different cannabinoid agonists. The mutations did not alter the basal stimulation levels but reduced the maximal stimulation (Emax). The L7.601 mutation significantly reduced the Emax for CP-55,940>WlN55,212-2>HU-210. In addition, the L7.60I mutation completely abotisheA [35S]GTPgS binding with SR141617A. These results suggest that Leu residue of tl Hx8 domain does not sigfiificantly contribute to the constitutive activity of the_hCBl receptor in this model system but is important lor activation of specific Gproteins. The differential stimulation obtained with the /tifferent ligands suggests that although SR141716A and CP-55,940 binding pockets are not related these ligands exclusively activate Gai3/Gao through L7.60 whereas HU-210 and WIN55212-2 can still activate the hCB1 probably by docking the IL3 domain to Gail/GaiP_ Dopamine modulates the intrinsic properties of layer II steHate cells in entorhinal cortex Araeri P.r, Heinemann Uf, Gutnick  Ddpamin reversibly ldi to a significant decrease in the amplitude of the sig. These effects of dopam on the intrinsic properties of such pivotal nourons in the parahippocampal circuitry may underlie, in part, the role of dopamine in neurologi_eal and psychiatric syndromes which involve defects in fhis circuitry., such as epilepsy and schizophrenia.

Supported by a European Community Marie Curie
Fellowship, the Alexander yon Humboldt Fndtn, and SFB 515.
'Virtual histology' of human white matter by diffusion MR imaging Assaf Y.e, Basser PJ.2 1lYre L-E2G Institute for Functional Brain Imetging, Tel Aviv Medical Center and Tel Aviv University "-Section on Tissue Biophysics and Biomimetics, I2MB, NICHD, NIH,Bethesda, MD, USA; Neuroscience in general and neuroimang in particular has evolved tremendously since the intr6duction of dynamic tupctional brain mapping. Despite the ability to follow task related brain activity, the structural network connecting these regions was only hypothesized from histological databases. Few years ago, the concept of diffusion tensor imaging (DTI) based fiber-tracking was introduced. This method is based on the anisotfopic nature of water diffusion in white matter. Parallel to the fibers the diffusion ears to be 'free' while peendieular to them it apars turbed. This quantity of white matter diffusion e-nhbles 3D mapping of large homogeneous fiber bundles= However, DTI suffers from inherent artifacts in areas ot heterogeneous white matter (crossing white matter bundles) and white matter fanning into gray matter.
Recently we developed an experimntal an/l theoretical framework to describe white matter diffusion even in areas of complicated white matter structures. The composite hindered and restricted model of diffusion (CHARMED) enables extraction of physical c9_mponents of neuronal structure based on their diffusion characteristics.
CHARMED assumes that the diffusion within the neuronal fibers is restricted while elsewhere is only hindered. With the distinction between restricted and hindered water diffusion it is possible to examine the microstrueture of neuronal white matter tissue. For example, parameters such axonal volume fraction, extra-axonal volume fraction, extra-axonal diffusivity and axonal diameter distribution can be extracted with CHARMED. Moreover CHARMED enables separation between heterogeneous white matter systems where more than one filSer-bundte passes and hence may enhance the fiber-tracking abilities.
CHARMEU based parameters help "to obtain microstructural information that limits virttial histology and provide a new tool to follow neuronal degeneration as well as white matter connectivity and integrity.
The Insulin-like growth factor mRNA binding-protein IMP-I and the Rhs-regulatory protein G3BP associate with tau mRNA and HuD protein in differentiated P19 neuronal cells Atlas R. Behar U Elliott E. and G'_mzburg I.

Rehovot 76100
Tau mRNA is axonally localized mRNA that is found in developing neurons and targeted by an axonal localization signal (ALS) that is locatedin the 3 tUTR of the message. The tau mRNA is trafficked in an RNA-protein complex (RNP) from the neuronal cell body to the distal parts of the axon, reaching as far as the growth cone. This movement is microtubule-dendent and is qbserved as.. granules that contain tau mRNA and additional proteins. A major protein contained in the granule is HuD, an Elav protein familymember, which has an identified mRNA binding site on the tau 3UTR and stabilizes the tau message /rod several axo.nalIy targeted rnRNAs. Using GST-HuD fusion.pr0.in as t)ait, we have identified four proteins contained within the tau RNP, in differentiated P19 neuronal cells. In this we studied two of the identified proteins i.e. IGF-II binding protein (IMP-I), the 6rthologue of chick 13-aetin binding Prgtein-ZBP1, and RAS-GAP SH3 domain binding protein (G3BP). We show that IMP-1 associates with HuD and G3BP-1 proteins in an RNA-dependent manner and binds directly to tau mRNA. We also show an RNA-dependent association between G3BP-I and HttD p.roteins. Tllese associations are investigated in relation to he neuronal differentiation ofP 19 cells.
Dept. of Neurobiolog/, The Weizmann Institute of Science, 76-100 Rehovot, Israel; Autoimmune CD4+T cells can mediate the ability to withstand neurodegenerative conditions. Here we show that the ability to spontaneously manifest a T cell-dependent protective response is resiricted by naturally occurring CD4+CD25+ regulatory T cells (Treg); deplefion of Treg was beneficial in two mouse strains (-C57BL/6J and BALB/c/OLA) differing in their spontaneous T cell dependent ability to withstand the consequences of optic nerve injury. Passive transfer of exogenous Treg was destructive in BALB/c/OLA mice (which can spg_ntaneously manifest a T cell dependent roteetive antis-elf response to "inj.tffy) but beneficial in C57,BL/6J .mice (which have o.rdy hmited ability to maniIest sucla a .response). This dithotomy was resolved by the finding _that., in severe combined immunodeficient rriice, a beneficial effect is obtained by__passive transfer of either Treg-free CD4+ T cells (Teff)or Treg alone; indicating that neuroprotection can be achieved-by .either Treg or Teff in the absence of the other. We attribute tle disparate effects of Treg to their differential interaction (in lart via IL-10) with local innate immune cells (microglia. in the pr_esenee and in the absence of effector T cells. Activation bf microglia by _pro and anti inflammatory_ cytokines in. suitab.ly controlldt amounts might _trigger difftrent signal transduction pathways, each of which induces a neuroprote.ctive micoglial phenotype. These results suggest that, under neurodeg_en_erauve conditions, the effects of Treg, and possibly also.of qther regulatory T cel_l_s, migl.t not be uhiform, and tlaat tlaeir expression ip different individuals .might be genetically determined Therefore, therapeutic intervention based on induction orregulatory T cells might have limitations. pse inhibition at 30 msec inter-stimulus-interval (ISI), vhich was reversed to a minor facilitation at 60 msec ISI. Surprisingly, only short-term but not long-term potentiation (LTP) was detected in. the nude mice. In-vitro, the dynamic rag.ge of the fEPSPs was similar in slices taken from nude mace compared with controls. Moreover, both the control and the nude mice showed similar paired-pulse facilitation across 4 different ISis. Strikingly, nude mice exprvssed sho term but not lon.g term potentiation of fEPSP. The.se restats suggest that adaptive ih_ uni is involved not onty in neuronfil-survival bur also in the maintenance ofneuronal plasticity, and .thus might shed ligtht on the role of the tmmune system in brain-learning aria memory processes.
The hebrew university of jerusalem Dept. of neurobiology institute oflife sciences; It is eqmmon knowledge that voltage-gated ionic, c.hanne.ls ge voltage sensors and also part oT ligand-gated channels show voltage sensitivi.ty ,although mucli weaker. In .contrast, y-protein coup.led rec. tors (GPCRs) involved in the majority of signal transduction p.rocesses are not considered to be voltage sensitive, although they are trans.m,embranal and eouqd pg.tentiall.y be mbdulat&l b.y membrane potential. In an earlier stud (Ben-Chaim et al., 2003) it was shown that two GPCRs, .the m2 (m2R) and the ml (mlR) musearinie receptors ,known to modulate neurotransmitter release, are vbltage sensitive; their affinity tgwd the agpnis_t..i_s .affected _by mqmbrane .ltential.
Another pe of GPcRs, me type 3 metabotrooic glut.a [nate reeept.or. (mGluR3) was also shown to exl.'bit voltage sensitivity H.ere we examine whether the tv0e la metabotrolic glutamate receptor (mGluRla), meriaber of group mGlu. ,exl#.'bit yoltage sensitivi.ty. Using .Xenopus oocytes we show that the type a meta.totropic glutamate reqeptor (mGluRla), known to participate in-LTD, is vo.ltage sensitive. The mGluRla, mediated, endogenous_ chlonle channel currents w.ere used to _say the activity el mGluRla. We found that the apparent amm.ty of mGluRla toward glutamate (Glu) was increased upon depolarization. Accumulation of iron at sites where neurons degenerate in Parkinson's (PD) and Alzheimer's (AD) diseases is thought to play a major role in the process of neurodegeneration. Th6 brain permeable iron clielator, VK-28, as well as the propargylaine moiety of rasagiline, exert neuroprotective activities in cell culture models and in vivo against a variety of insults. We developed, a novel bifunctional drug M30, .l?ossessing these components. M30 (1-10 rmcroM) decreased apoptosis of SH-.SY5Y neuroblastoma (NB) eel.ls in a neuroreseue, serum deprivation model, via multiple protection mechanisms, including: r_eduction of the pro: hpoptotic Bad and Bax; reduction ot apgptosis-associated S-er139 phosp_holated H2A.X; induction of the anti-apoptotic_-Bel-2; inhibition of the cleavage and activation of caspase-3. Moreover, M30 promot&l morphological changes resulting in axonal growthassociated protein-43 (GAP-43) implicating neuronal differentiation. VK-28 did not show any significant effect on cell differentiation. M30 markedly reduc&l holeamyloid precursor protein (APP), C-terminal fragment (CTF) -beta levels and the _.a[nyloidogenie A-beta peptide, in NB eell_s and in Chinese Hamster ,,Ovary (CHO dells stably transtected with A. PP "Swedish mutation, the in cell media and the, in a dose dependent manner. In correlation, the non-amyloidogenie soluble APPa levels were elevated as well as the levels of CTF-alpha in cell lysate. These results co_mpliment the presence of an iron-responsive element (IRE) in the 5"untranslated region (5"UTR) of the APP and the iron chelator properlaes of the drug. The bifunctional drug, M30 possesses neurorescue, neurodifferentiation and-APP resulting in a substantial reduction_ in A-beta vels, miat be a novel drug for the treatment or AD. neurotransmitters and neuromodulators in the: central nervous system via specific reeept?rs. Recently the endocarmabinoid system w.as found to tm involved m the vasodilated state assocmted with cirrhosis. We hypothesized that the endocannabinoid system m.ight also have a role in the lathogenesis of hepatic eneeohalppathy in an exoerimental .mo0el of fulminant hepatic ffilure. .Methods: Tulminant hepatic failure in mice was induced by thioacetamide. Neurological performance was assessed by a ten ooint scale, by activity and by cognitive tunction.
Central Control of Bone Mass Bab I. Bone Laboratory, The Hebrew University of lerusalem, Jerusalel; In vertebrates, bone mass is maintained constant between the end of lear skeletal growth and gonadal failure by a continuous destruction/formation process termed bdne .remodeling, _which occurs simultaneously in multiple loci. It consists 9.t a resorption ph.ase of_ p.re-exist.ing bo.ne by a. specihc cell type, ,the osteoclast, tOllowed ty a phase"9t bone formation b another b.one-specific cell type the osteoblast. Although different foc present different phases 9f the cycle, the overall net ettect is that of a bhlance tetween bone destruction and formation. The phvsiol.ogic importance of. bone remodeling .is best illus.frated in osteqporosis, the most common degen_erative disease in.
develop.ed countries, which results trom an impaired remodeling balance that leads to bone loss and increased fracture risk. Several lnes of evidence suggest that bone remodeling is .centralls 9ontrolled: 1) Bones are densely innervated-by the symlSathetic nervous, system as well a,s.by, sensg.ry nerve fibers containing calctonin genezratea peotide, substance P and tyrosne hydroxylase. 21 tqne ceils expr.ess receptors for "these and other neurotransrmtters, suggesting the occurrence in bone .of a non-.synaptic, diffuse, and slow neurotransmit.ter signaling whicli re,ukites bone cell differentiation and activity. 3) Clinically, obesity orotects against bone loss induced b).' the cessation of godal (unction: 4) Pe.rhaps the most direct evidence for the central control orat least bone formation is pathophysio-logy of Alzheimer disease (AD). Npropargylamine markedly decreased holo-APP levels, accompanied by increasedlevels of the non-amyloidogenie a-seeretase form of soluble APP (sAPPa) into the medium. Similar effects on cell survival and APP rgulation/processing were demonstrated for rasagiline. These results indicate that the regulatory effects of rasagiline and N-propg3,lamine on APP and sAPPa levels promote a reductmn in the toxic amyloidogenie pathway, revolved in AD. It is well documented that odd dements e easily when embedded in a field of distractors that are smtlar to each_other and differ categorically from the odd.element in one lea__tu;e, such as color, ori enfation motion direction shave. We ask whether e relevam shape heeds to be defined by real edges or do_illusory, contours (Kanizsa, 1979) als6 induce a. pop-out ca_eet,. the.ugh theix per.eeptio.n. is slower, and to wlrat extent does such a lOl-OUt on illusory-contour gaining history. FrexioL_ stu.es inye.stigated the possibi of a pop-ott, etteet when subieets search for a set of illusory-contour inducers afield of non-inducers (Grahow  .'al.s)_ is relevant also for slowly induced p..epts. A siifieant difference in per(o.rmane as elt as in 1 raie was fonnd betweet/subjects with different levels training. In contrast, a contrgl .ement with real (rather than iffu,ry) .figuyes showed silaifieantly less. dependence .on training level. These results suggg. pop-gut. detection 5f Kanizaa fiffures is a ft,&ion o1 . S.uppqe d by "Center ofcett.enge'" grmrt #8009from the Hippocampal sharp-wave Benrens C.J. lnst for Physiology_, Dept. of Neurophysiology, Charitd U Med Cntr Berlin, Germany; Hippocampal harp-wave tipple complexes (SPW-R) occur during slow xave sleep andbehavioral immobilitv and are thought to r.epresent stored information that is tran[ferred to the cortex m a process of memory" consolidation. Here we show that stimuli which induce long-term potentiation (LTP) a neurophysiological correlate of learning and memo'ry, led to generation of SPW-R in hippocampal area CA3 that were ide.ntical to thos.e, observed s.pontaneously.
Following repeated stratum radiatum-stimulation in area CA1 evoked SPW-R recurrently occured in area CA3 and propagated into area CA1 and the subiculum. The induction of SPW-R was dependent on activation ofNMDA receptors and involved time-dependent changes in .interactions between clusters of neurons in the associational network of area CA3. Furthermore the induction of SPW-R by high frequency stimulation (HFS) could be revers by application of low frequency stimulation (LFS) which also reversed stimulus-induced LTP in area CA3. During _application of low dose acetylcholine (ACh) in presence 6f ACh-esterase inhibitor physostigmine a facilitation of the stimulus-induction of SPW-R was observed as well as a bockade of SPW-R activity by application of a ten fold higher dose of ACh. Our data suggest a mechanism which, b) inducing SPW-R in the hippocamPus, can be used to explore their role in emory consolidation, as well as the rules governing netork activity in areas CA3 and CA1 and, tfierefore, the generation of ensemble activity in this structure. Furthermore these results suggest that, under certain cogrfitive states, learning-induced synaptic plasticity might result in the generation of SPW-R and .the propagation of information from the hippocampus to the neocortex.
'School Of Electrical Engineering, Faculty of Engineering, Tel Aviv University, TeFAvv; The Wohl lnstitut for Advanced Imaging, Tel Aviv SouraskyMedical Center, Tel-Aviv; Binaural processing of sound in humans is initiated within the audito nuclei in the brainstem. An MRI study on patients with multiple sclerosis and stroke indicated that whenever the lesion overlapped the brainstem audito" pathway, some binaural pcrfo/'maneo was abnormal, whilb he monaural performance was normal. The purpose of the present study is to reveal the difference between binaural hnd monaural processing using functional MRI (fMRI) on healthy subjects, fMRI was performed on a 1.5 Tesla GE scanner. Axial, sagittal and coronal slices of 4 mm thickness and 0 gap were acquired. A GE-EPI sequence was used with TR based on fide ECG and configui,ed to every fourth heartbeat. Statistical analysis of the data was perf0rmed by using SPM2 software. The default boun_.ding box of SPM was idjusted to include the brainstem. Since the brainstem auditory nuclei are relatively small structures, the_analysis included removal of movement related artitacts. The analysis was per(.ormed only in the sub-.cortical area...The auditory activation was mapped on a 3-D brainstem auditory pathway atlas. Fifteen young healthy subjectsparticipated in the study. Subjects were stimulated by 20-30 seconds of either classical music or rock music Presented binaurally or monaurally. In all subjects, binaural stimulation yielded aetiva.tion in at least one brainstem nucleus. Actwation was identified in the cochlear nucleus, su .le.rior olivary complex, and inferior eolliculi. Both fight and left auditory pathways were activated only when brth ears were stiniulated. The fight auditory pathway was primarily activated when the l-eli ear was stimulated and vice versa. We have demonstrated that fMRI can be used to identify, the brainste.m autory pathway.. Further investigation is required to explore the auditory pathway with different stimuli. Dept. of Phvs/ology and Pharmacology, Tel-Aviv University. Tel-Aviv G-protein coupled receptors (GPCRs) are involved_ in most signal transduction processes. Although GPCRs are transmembranal and could potentially be modulated by membrane potential, they are not considered to be, by themselves, voltage senffitive. In an earlier study (Ben-Chaim et al., 2003 J. Biol. Chem. 278(25), 22482) we showed that two GPCRs, the m2 (m2R) and the ml (mlR) muscarinic receptors are voltage sensitive; their affinity .toward the agomst is affected by membrane pgtential. We hypothesized-that membrane potential affects the coupling of-the G-protein to the receptor and thereby determines its affinity; hi,gh affinity when coupled to the G-protein and low affinit3 when flee. This hyp:oesis was tested direcfl bx_ measuring the voltage dependence of the agonist s atlinity_ of chimeric mlR and m2R in which the third intracetlular loops were interchanged. We show that the voltage sensitivity of both mlR and m2R crucially relies on the l.oop that couples the receptor to its respective G- In the progression from suckling to weaning, rat pups show a reduced preference for the mother rat in a choice situation. We report here that 31-day old weaned rats who are expo_sed to 30-minutes of acute stress revert to an earlier mode ofbehavior reminiscent of the suckling stage that of preferring the mother rat. Sprague-Dawley derivbd male rat pups (n=21) were tested for preference in a Y-maze, where one arm contained the dam g.nd where one arm contained a female littermate. When the pup made a choice, the trial was terminated. Each animal was evaluated for choice 4times at different posmatal ages, once as a suckling at 16-18 days and three times as a weanling at 30 31, and 34 days. Prior to the choice test on day 31, pups'were placed on small elevated platforms for a period of 30-minute.s, a method commonly used to induce stress. They were then tested as usual fo preference for the dam or httermate. In keeping with previous work, 70 % of suckling pups (16-18days) refe_rred the mother as compared wtli 6nly 33 % preference for the dam in weaned rats on day 30. However, tmmediately after the platform stress on day 31, signi'fieantl more of these weaned rats (71%) reverted back to preferring the mother much as tl.y had done as sucklingS. This stress-induced preference shift wa.s largely reversec] on the following trial on Day 34 without the stress manipulation, with only 43% of the weaned pups preferring the dam. These results suggest that stress may cause a regression to much earher s.tages of soeio-affective development. We speculate whet-her this phenomenon, observ&t in laboratory .rats, may be related to instances of stress-induced regression or attachment reported by clinicians in humans.

Sixty-Minutes per Day of Social Interaction Reverses
Isolation-lnduded Aggression and Increased-Morphine Consumption Berber B.D., Teucher D. and Raz S.

Delft. of Psfc_hology Brain and Behavior Research Center
University OfHaifa HaiJi 31905 Laboratory rats that are housed in social isolation are more aggressive and consume more morphine solution than .socially. housed rats. We report here that 60--min. of social interaction per day. reverses these effects of isolated housing. In one series of studies, pairs of male .rats were trained in a cooperation task where both animals must coordinate their behaviors to receive food reward. Following acquisition, subgroups were allocated to one of three housing conditions: 1) social housing (2-per cage); 2) social isolaqon (1-per cage); or partial social isolation (1per cage witla access to ariother male rat for 5-min, 60-mm, or 4-hours per day). After 21-days in these different housing conditions the animals were re-tested in the cooperation task. Significant deficits in re-test c.ooperation perf.o_rmance and increases in aggression were observed, in animals with 0 or 5-min. per day of social interaction. No deficits were observed in subgroups that had at least 60minutes per day of social interaction. In parallel studies, male rats were housed for 21-days in one 6f three housing con.ditions: 1) social housing (2-per cage); 2) social isolation. (1-per cage); or 3) partial social isolation (1-per .c.age with access to another male rat for 60-min per day). water or 0.5 mg/cc morphine sulfate consumptaon were measured in one-bottle or two-bottle tests. Socially isolated animals consumed significantly more morphine but not more water than those m the social housing or partial social isolation groups. There was no differefice between the sial housing and the partial social isolation groups indicatin.g that 60-minutes of social contact per day is sufficienf to reverse the effects of social isolation. Taken together, these studies indicate that social isolation increases aggression, disru_ a CO0perat'_a le_aming_' task, and increases morphine intake and that a short daily period of social interaction reverses these effects of social isolation.
Activity and significance of the brain ZnR Besser L., ChorinU., Rimon U., Sekler I., Hershfinkel M. Dept-:=of Morphology and_ Physiology, Ben Gurion University of the Negev, Beer-Sheva, 84105, Israel Dynamic changes in zinc play a k physioloeat role i. synaptic transmission, and are a leadifig factor in neuronal death following excitotoxic syndromes attributed to neuronal zinc rise. We propose that ZnR, an extracellular zinc sensing receptor is mediating intracellular signaling following hanges in extracellular zinc concentrations.
Indeed Ca" signals are monitored in acute hippocampal and neocortical slices following application of extraceltutar zinc, particularly strong activity was monitored in the CA3 region. Using TPEN, a membrane p_ernable zinc chelator, we demonstrate that the rise in tile C"a z+ sig_L following ZnR activation is indeed related mostly to Ca z+ and not induced by znz+ perrncation suggestin that jmpo_rtant cellular signaling is triggered by extracelffilar Zn and not 0nly by its permeatton in neurons. The brain ZnRdependent calemm rise,is mediated by the IP3 p__athway such rise in intracellular Ca"* has been previously linked to the modulation of LTP and LTD, and neuronal apoptosis on the other, hand. A major pathway that may convey the metal0._tropic signai_ to neuronal death or survival s the MAP kinase pathway. We have indeed monitored the specific phosphorylation of ERKI/2 following brain ZnR activation. The potential physiological significance of a zinc sensing mechanism is shown-by the extremely wide range of zinc concentrations activating the ZnlL ranging from nanomolar to micromolar. The extremely high affinity of brain ZnR is intriguing since it is expec[ed to be activated by minute, subtd.,dc zinc concentrations, which we see released following electrical stimulation. NMDA channels in superficial neurons of the mouse presubiculum containNR2C subunits Binshtok A. , Aracri P., Fleidervish  We studied the me.e that mediate le.a,sning-rel_aed long lasting reduction of the post-burst attcr hype.rpolarizafion (AHP) in cortical pyraniidal neurons. We pv_iously showed that pyram.i.dal neurons in th.e rat iiriIOrm cortex from olfac_t0__ry-discrimination trained rats have reduced l_St-burst AHP for three days traimng completion, ahd that this reduction is due to decreased conductance of one or more of the PKC and calciumdependent potassium current that mediate the medium anor the slow AHP. In the present study we examined which potassium current is modulated by learnin.g, and further explored the molecular mechanism that enables its long-term reduction. The small conductance (SK) channels inlfibitor, apamin, reduced the AHP in n.en..ons from trained, naive and pseudo trained rats to a similar extent, thus maintaining the difference in AHP amplitude between neurons from trained rats and controls. The protein expression level of the SK1, SK2 and SK3 channels was also similar in all groups. Noradrenalin (NE), which was shown to enhance the IAHP while suppressing the SIAHP, enhanced the AHP in neurons from trained rats, indicating that sIAHP conductance is reduced after, learning. TI MEK inhibitor PD98059 increased the AHP ohly in neurons from trained rats, thus abolishing the differences between neurons from trained rats and controls.
Accordingly, neuronal excitability was d.ecr.eased in neurons from trained rats only. We suggest that lear.inginduced enhancement of neuronal excftbility is mediat by reduction in the sIAHP and that this long-term reduction is maintained by ERKFII activation.

11
Cyt_otoxic or neuroprotective? The context-dependent activity of microglia under neuropathoiogical conditions Butovskv O:, Talpalar AE., Ben-Yaakov K. and Schwart M. DTO t. of Neurobiology_, The Weizmann Institute of Science, 0 Rehovot, Israel; 'Protective autoimmu_nity' refers to a well-controlled T cell-mediated anti-self response that helps the body resist neurodegeneration. Using an in-vitro assay of hippocampal slices to assess the cotoxic or protective effect of microglia in neural tissue we show that interferon (IFN)gamma and especially interleukin (IL)-4, characteristic Thl md Th2 cEt_okines, respectively, endow microglia with a protective Ohenotype. Ifi contrast, aggregated befa-amyloid, like bacterial cell-wall-derived lipopolysaccharide (LPS), evoked a cyt_o_toxic microglial response. C)totoxicity, was correlated with a signat-transductlon pathway that downregulated MHC-II expression throtigh the MHC IItransaetivator and the invariant chain,-Protection by IL-4 was attributed to down-regulation of TNF-alpha and upregulation of insulin-like o.wth factor (IGF-I). These findings suggest that beneficial or harmful expression of the Iocal immune response in the damaged CNS depends on how microglia interpret the threat, and that a well-regulated T cell-mediated response enables microglia to alleviate rather than exacerbate stressfid situations hi the CNS. Cell renewal in the central nervous system (CNS) of adult mammals is limited, and is blocked in inflammatory conditions of the brain. Here we show that both neurogenesis and oligodendrogenesis from adult rat neural progenitor cells are blocked by inflammation-associated (endotoxin-activated) rat mic'roglia. However, when activated by IL-4, a cytokine associated with helper T cells, the microglia induce and support neurogenesis ,and oligodendrogenesis. Blockage and support of neurogenesis were correlated with UP-and down-regu.ation, respectively, of microglial production of TNF-alpha. Oligodendrogenesis induced by IL-4-activated microglia could be neutralized by specific anti-IGF-1 antibodies. In vivo, hippoeampal neurogenesis and cortical oligodendrogenesls were significantly boosted by IL-4-activated microglia injected into the cerebral ventricles, but were blocked By microglia activated by end.otoxi.n. These findings suggest that immune modulation, ratlaer tlaan anti-intlammato treatment, is likely to promote repair and cell renewal in flae adult CNS. Introduction: A new study has just been funded by the NIH to study CJD in Israel. We will use neuroimaging to elucidate early, and even premorbid, cerebral abnormalities of structure and ftmction in asihgular cluster of high incidence occurring among Lib)a_n Jews li.-ing in Israel, caused by familial transmissio ora mutated pnon protein (PrP) gene. All subjects will have extensive neurological and neuropsychological examinations, as well as MR/, using both traditional structural imaging and newer neuroimaging methods: Diffusion-Weighted Imaging (DWI) and Magnetic Resonance Spectroscopy (MRS). Here we present the general logic and structure of the study, as well as resulis from the first seven subjects (4 patients and 3 relatives). Results: On clinical readin'g of the MR/s, all three controls were judged normal, and all four tents were considered abnormal. The most common ings were FLAIR and DWI hyperintensity in caudate (4/4), putamen (3/4), and cortiga] white matter (3/4). Quantitative analyses showed significant loss of gr matter and higher ADC values in cortex Focal decreases of ADC were found in the lentiforrn nucleus of patients.
Spee.troscop!c imaging demonstrated reduced N.AA in. the patients, wth the NAA/Cho r.atio lowest in cingulate gyrus, where was also correlated with a neurological severi score. Duration of disease was correlated with this ratio in the caudate nucleus and putamen. Comment: This project is the largest neuroimaging study ever conducted in CJD and the first to observe a genetically homog_enous sample. It will provide data on the earliest stages Of the disease, and on healthy mutation carriers before frank onset of_ symptomatology. The  Hippocampal dissociated cultures were differentially exposed to. 400mT magnets and monitored by calcium imaging (at 10Hz), combined with morphological comparisons of GFP ii'ansfected cells in these cultures. We checked both acute and chronic effects on network arameters such as spontaneous burst frequency (SBF), urst synchronicity, burst decy time and fluorescence dynamic range (DR max amplih.demin base level). The acute treatment (immediate exposure to SMF while recording) showed little effect with very_ large variability in all parameters. The chronic treatment (11-12 days owth with the magnets) showed, on the other hand, sigmficant effects. These expq.sed cultures showed a large increase in SBF, a small decline in maximal DR and synchronicitv decline that was significant in the north magnetic pol treatment only. This unexpected asymmetry was even more pronounced in the effects on the dendritic trees morphology (Sholl analysis): south magnetic pole exposawe reduced th branching at 100-150um dtstance from thesoma, compared to the control, whereas north magnetic pole exposure increased the branching at the distances of 50-150um (both were insignificant in Other distances). Our results suggest that a conic exposure to a strong SMF affects the neuronal network activity as well as cell morphology. Nevertheless, further research must be done before makin-g any conclusions regarding the impact of these effects on the mammalian nervous system and humans' in particular. Dept. ofLife Sciences and the Zlotowski Center for Neuroscience, Ben Gurion University; One of the preferred expression systems for the study of ion channels employs Xenopus oocytes. Charmels mRNA is synthesized, injected to oocytes and induced ionic currents are measured by the Two Electrode Voltage Clamp (TEVC) or the patch clamp techniques. To explore channel activity, oocytes are held at various membrane potentials and exposed to a variety of external conditions. Here we studied the effects of common experimental conditions on the phosphorylation levels of membrane proteins as phosphorylation/dephosphorylation events modulate ion channels gating and cell surface expression, Two strategies were chosen to determine relative phosphorylation levels: a direct detection with a phospho-Ser/Thr PKA subsrate antibody and a functional method employing two different 12 leak potassium channels, as indicators. The two channels were chosen for their opposite responses to protein kinase phosphorylation: Drosophila KCNK0 channel activity is enhanced while human KCNK2 channel activity is reduced several fold following protein kinase A (PKA) activation. To eliminate possible modulation by pathways other then phosphorylation, mutants that are impaired in their PKA regulation were tested. We found that experimental conditions had a dramatic effect on the measured ionic eta'rents: even a few minutes exposure to "physiological conditions" (4mM KCI, -80mV) decreased KCNK0 currents while increasing KCNK2 currents --3 fold. Similarly, dramatic opposite current changes were observed while altering oocytes holding potential or bath solution ion composition, temperature, pH or osmolarity. On thecontrary, mutant channels were not influenced by the same conditions. Correlating variations in phosphorylation levels were detected in un-injeeted oocytes by western analysis. We conclude that common experimental procedures dramatically affect phosphorylation levels in Xenopus ooeytes. The use of kinases/phosphatases modulators might reduce uncontrolled effects on expressed channels. Structure and Pathology in the Central Nervous System by q-Space Diffusion Weighted MRI Cohen Y.

SchOol Of Chemstt3; The Sackler Faculty of Exact
Sciences, Tel Aviv University, Israel; Magnetic Resonance Imaging (MRI) is currently the most important imaging modal\ty iaf the central nervous system (CNS). The main reasons f6r that is the non-invasiveness of the method, the .many physical parameters that can be used as contrast mechanisms to construct MR images and .e fact that morphological information can be coupled with biochemical information using magnetic resonance spectroscopy. (MRS). Diffusion s an mportant contrast mechanism in MRI of the central nervous systems (CNS) with applications ranging from early detection of ischemic injury_ to fiber tracking. In the lecture we will describe the principle and selected applications of high b value q-space liffusmn MRI in the CNS. Applications ranging from structural studies in excised spinalcord, througli-detection of different white matter associated pathologies of the spinal cord up to in vivo applications 6f this technique in MS and Dementia will .be described. These ex.amples will be used to demonstrate the pgtential and limitations of this technique. At the end of the lecture, if time will permit, we will highlight some new avenues of MRI in experimental neurology had neurobiology.
Autoantibodies against an extracellular pept_ide.of the GluR3 subtype ofAMPA receptors acticate both homomeric and heteromeri AMPA receptor channels Cohen-Kashi K., Ganor Y., Levite M. Teichberg V.I. "Dept.: of Neurobology, The Weizmann Institute of Science, Rehovot, Israel; Saclder Faculty of Medicine, Tel-Aviv University, Israel; Autoimmunity may contribute to the pathology of some epilepsy syndromes as the sera of some epilepsy patients harbor specific autoantibodies to the GIuR3 subtype of AMPA/glutamate receptor channel. Building on previous reports of a glutamatergie agonist activity of anti-GluR3 sera we investigated here the ability of affinity-purified Abs directed against the GIuR3B peptide (a.a 372-395) to bind and activate recombinant GluR3 receptor channels expressed by Xenopus oocytes. We found that affinitypurified anti-GluR3B Abs can by themselves activate both homomeric and heteromerie GluR3-containing channels without the requirement of neuronal, glial or blood ancillary molecules. When repetitively applied, anti-GluR3B Abs didn't cause receptor desensitization. Coapplications of anti-GluR3B Abs and glutamate displayed neither inhibitory nor synergistic effects, and preincubation with anti-GluR3 Abs didn't affect the subsequent response to a glutamatergic agonist. We therefore conclude that anti-GluR3B Abs can activate Glur3-containig receptors, and hypothesize that if present chronically in brain fluids, these Abs may lead to a detrimental activation of GluR3-containing AMPA receptors. These findings may have important clinical relevance to epileptic patients harboring anti-GluR3B Abs. ERKI/II is essential for maintenance of olfactorylearning induced enhancement of synapfic transnsion in the lriform-eorlex.
Previous studies have shown that olf_aeto_-discrimination learning is accompanied by reduced paired pul.e facilitataon (PPF) in response to stimuli applied to the intrinsic fibers, interconnecting layer II pyramidal neurons. Extracellular regulated kinases (ERKI/II) are thought to play major role m learning and memory as well as sptie plas.ticify in the brain. The purpose of the present s.tuay was to determine whether ERKI/II-has a role s maintainirig the olfaetg.ry-learning induced reduction in PPF. Intraeellular recordings from pyramidal neurons were 1_.rf_p.rmed in pixiform cortex brain slices. ERKI/II ihhibition by application of PD98059 (38 tM) had no effect o. PPF values in neurons from naive and pseudo trained rats.
However, it caused a significant increase in PPF value in neurons from trained rats. Consequently the difference in PPF values between trained and the controls was diminished (from 1.24 + 0.04, n=19 to 1.42 + 0.08, n=9 in trained, from 1.4 + 0.04, n=16 to 1.51+ 0.06, n=lO in pseudo trained, and from 1.39 + 0.07, n=18 to 1.31 + 0.07, n=l 8 in naive). In agreement with the electrophysiologieal analysis, Western blot analysis of synpatosomfil fraction, showed an increased ERKIJII activation (4(Y%) in brains from trained rats (n=5) compared with control brains (naive n=7, pseudo trained n= 9). We conclude that ERK_I/II activation is essential for maintenance of learning-induced enhane.ed synaptic .transmission in, the piriform cortex. We e,urrently a.tLn to identify ERKI/II s p_resynap.tic .substrates ttmt are meaiating the learning induced synap-tie plasticity.
Neurobiol, Martinsried, Germany; The lobula plate tangential cells in the fly consist of a set of 60 strongly interconnected larg e field motion sensitive intemeurons. This small network of cells has shown to exhibit a number of different computations associated with precise and unique wiring. In this study we focus on a subset of these intemeurons, the vertically sensitive VS cells. VS-cells were shown to have complex receptive fields extracting particular features of the 0ptie flow that result e.g from rotational ego-motion. Based on dual recordings from VS-eells, it was suggested that neighb0 _rin.g. VS cells are electrically coupled and distal cells inhibit each other (Haag and Borst 2004). Here, we analyze the suggested connectivity scheme using realistic comparmaental modeling. Our calculations indicate that such a connectivity results in a linear decay of the signal from one cell to the other along the horizontal visual axis and can reproduce the experimental data available so far. The functional implications of this orderly arranged connectivity will be discussed. The involvement of the frontal lobe in memoD' processes is long acknowledged. However, the exact role it plays is controversial. In recent years, both monkey and human studies have established the role of prefrontal cortex in maintenance of information across delays in working memory. As for retrieval of information however, it has been asumed that the frontal lobe is involved only in postretrieval processes (i.e., assessing the outcome of retrieval). Following a hint from an fMRI experiment, we compared event related brain potentials during encoding and retrieval of faces in a delayed match to sample task. We asked 15 participants to remember a briefly presented face over a period of 2 seconds and then judge whether a second face is of the same person or not. The response was separated in time from the presentation of the second face. We found that the N170, a marker of face perception, recorded over parieto occipital scalp sites, s identic}d during the presentation of the first and second face. However, during the second presentation, when retrieval is required, a frontal scalp activity starts around 80 ms after the face is first presented With the limitations of EEG measures to identi_fy sources reliably this suggests early recruitment of frontal lobe mechanisms in retrieval, inconsistent with a merely post-retrieval process. We progose therefore that the frontal cortex is involved with retrieval from the outset. and that increasinDHEA levels may assist in withdra.wal from cocaine-seeFdng behavior. We decided to induce withdrawal_from cocaine seeking behavior. So, we .exposed a group or rats to cocaine using the self-administration technique. When.rats achieved matntenance levels meaning they take a steady amount of _drug on a daily basis, the_ received daily i.p injections of DHEA (2 mg/kg) for 2 w.eeks, 90 fnimites before being placed iri the sqlf-admimstratiOn chambers. We exammdd the possibility that wfi.ere the object's position and veloe.ity (of both distractor and target) are mampulated. Method: In phase 1, the system is used to assess the motor performance of young adult h.ealth subjects, an.d focuses on the influence of the object s velocity, on the attenti_onal mechanisms underlying the planning and execution ot movements in 3D.spaee. In phase 2, tlie system will be used to assg.ss the motqr .perfprmance of elderly healthy subjects and patients with strgke. P.hase 3 will iddress ssues of design usability in order to demonstrate, the feasibility of using such a system for rehabilitation evaluation and treatment. rrcquenc .es. For this reason we used a special stim.ul the transposed stimulus, for our study. Transposed stimul are composed of a low-freq_ueney envelope rectified and lowpass filtered to simdlate auditory nerve processing, multiplying a high frequency tone or noise earner. To test lateralization, the envelope consisted of a ban@ass noise centered at 4 different low frequencies, and the transposed stimulus was presented at different ITDs. In tests of binaural detection, the envelope consisted of the sum of a tone and a noise at different szgnal to noise ratios. The tone was added to the noise at both ears with the same phase, simulating a diotic condition, or with inverted phases to the two ears, simulatinga dichotic condition. Whereas it is commonly stated [hat neurons in A1 cannot follow repetition rates above 20Hz, using the transposed stimuli we observed neurons that locked to the fine structure of the envelopes even at 128Hz. Many neurons with high best frequency (6-15-1d-Iz) showed sensitivity to ITD, a result that has not been reported before. However, ITD tuning did not appear at all the envelopes confi_ggrations but was.often restricted to a scific envelope and carrier types. When using an Optimal stimulus configuration, ITD-sensitivity was exquisitely sharp, with some ITD tuning curves showing a peak width of 200 is. Many neurons also showed binaural masking level difference, with the tone affecting the neuronal responses at substantially lower level in the dichotic condition than in the diotic condition. However, serum testosterone levels, measured by radioimmunoassay, were similar in CMS and control mice.
Since depression was induced by exposing the mice to various stressors, and because glucocorticoids inhibit bone formation, CMS-induced enhancement in their serum levels could lead to bone loss. Indeed, immunoreactive corticosterone levels were almost twice as high in the CMS mice compare.d to controls. The anti-depressant drug imipramine, adminstered in the drinking water, reduced the depressive symptoms as well as the accompanying boneloss in mice sutjected to CMS. Concomitantly, mipramine blocked the increase in corticosterone levels m these mice.
Finally, signaling via the .hypothalamic leptin receptor, ObRb, hasbeen recently imphcated in the central control of bone mass. Specificallyr leptin signaling is a negative regulator of bone formation. Indeed, CMS mice showed a significant increase in hypothalamic ObRb mRNA levels as measured by real-time RT-PCR. To conclude, the bone loss that accompanies the depressive-like state in mice exposed to CMS may be mediated by several mechanisms. Our results suggest corticosterone and leptin signaling, but not gonadal hormones, as possible mediators. Surge" is characterized by_ elevated levels of pronflammatory cytokines, including interleukin-lbeta, and by hyperalgesia. It is also characterized by activation o.f the hypothalamic-pituitarv-adrenal (HPA) axas, by elevated levels of adrenocorticotr'opin (ACTH) and cortmosterone (CS), and secretion of prostaglandin E2 (PGE2) in the periphery and in the brain. Effective perioperatve pain management can attenuate activation of the HPA axis and improve recovery (as assessed by body weight (BW) and food consumption (FC)). The present study examined the effects of two 19erioperative lain management techniques on FC and BW following Iaparotomy in rats. All rats received an intrathecal (i.t.) mixture of mo.rplh.ne plus bupivaeaine before the incision. This preemptive injeeiion was combined with one of two treatments: 1) injection of slow-release morphine at the end of the surgery, or 2) an anti-inflammatory agent, IL-1 receptor antagonist (IL-lra), combined with the preemptive i.t. mixture. The effects of erioperative pain management on PGE2 levels in several rain regions, and on plasma levels of ACTH and CS, were also examined. A significant analgesia was achieved by both treatments. Laparo_tomy significantly decreased FC and BW. Both analgesic treatments resulted in faster recovery of FC and BW; this beneficial effect was more pronounced in the group receiving preemptive analgesia cnbined with IL-Ira, suggesting that IL-Ira contributes to a better postoperative recovery. Laparotomy elevated CS and ACTH plasma levels, and brain PGE2. Analgesictreated rats exhibited attenuated elevation of 131asma stress hormones, and of PGE2 levels, especially in the amygdala.
Thus, effectiv.e preemptive analgesia improved postsurgical recovery, and attenuated surgery-induced HPA activation and elevation of brain PGE2. Since PGE2 is involved in activation of [he HPA axis, the present findings may suggest a mechanism by which paiia relief reduces stress response to surgery,.
Neurons work for a living. Fishbein I.., Greenberger V. and Segal M. et. ofNeurobiology, Weizmann institute of science, enovot Constant network activity is a common feature of neuronal populations throughout the CNS. This activity can be nduced by afferent input, or produced spontaneously in the network, as is the ease during embryonic development and sleep. While the mechanism by which, too muh activity damages neurons has been extensively studied, little is known about how might the lack of activity harm the cells.
To study this phenomenon we used primary cortical cultures, deprived of their normal spo.nta_eous activi_ty by_ the sodium channel blocker tetrodotoxin (TTX). We ftund that blocking the network activity had a slow yet devastating effect on neuronal populations. Nearly all the neurons died within two weekd, unless provided with an extrinsic s.upply of brain derived neurotrophic factor (BDNF), which produced a partial rescue of the cells. The slow neuronal degeneration was accompanied by morphological shrinkage of the neuronal soma and dendritic arborization. On the other hand, Miniature excitatory postsynaptic currents (mEPSCs), increased after long term exposure to TTX, both in amp.litude and .in frequency. Surprisingly, abolishing network activity 19y blocking glutamate reeelgtors did not produce any neuronal death. Furthermore when the AMPA receptor blocker DNQX was combia'ed with TTX treatment it dramatically diminished neuronal death. We suggest that the upscaling of mEPSCs in the absence of action potentials plays a role in the chain of events leading to neuronal death. We also suggest that a possible coupling between BDNF release and action potential discharges offers a partial rescue of the activity deprived neurons.
Regulation of the glial inflammatory response by selective agonists for somatostatin receptors.
Dept. of CtinWal Pharmacology, Ben-Gurion of the Negev, POB 633, Beer-Sheva, Israel; Chronic inflammation is involved in the pathogenesis of neurodegenerative disorders such as Alzheimer s disease (AD) and Parkinson's disease (PD). This chronic inflammatory response is charact6rized, among other things, by reactwe gliosis in which as.trogytes..ao.d. microgliaI cells are activated and proliferate. Activated glial cells are a major source of inflammat_o.ry mediators such as pro.staglandins (PGs) and cytokines. The aim of the p.resent sm,dy was to investigate tlie role o.f som.ato.statin (SS.) and selective agonists for SS receptors (sstr) in the regulation basal and gpopolysaccharide "(LPS)-induce.d PG.producfion in micrqglia and astrvtes. Our results show that SS and octreotide, agonist to sstr 2,3,5 inhibited basal PG synthesis by 2-5-32 and 4_5-77% respectively in astrotes Selective agonists lor sstrl, sstr2 and sstr3 reduced 15asa astroce PG production by 35% 32% and 19% respectively. LPS increased PG synthesis in microglia and astroces. SS and octreotide inhibited LPS-mduced microglia! PG synesis by 80% and 62% respectively _but, did not c.h.ange -LPS-induced PG levels in astroces. It is .suggested that if microglial PG syn,thesis that is irid.uced .by inflmmato.ry agents like LPS is significantly .regulated 19y SS and analogues, then Sl.cific preventive and tl3.e.rape.utic modalities may be devised to intervene with these mechamsms. Del of Biochem, Technionlsrael Institute of Technology, The B. Rappaport Faculty of Medicine, Haifa; M.ammalian brain contains high levels of D-serine an_ dogenous coagonist of N-mL-thyl D-aspartate tyl. of glutamate receptors. The presence of D-senne in the brain challenges the dea that only L-amino acids will be present or play a role in mammals. We now sought to undirstand the mechanism of biosynthesis and degradation of brain Dserine, which will shedlight on severaq aspects of D-serine in neurobiology.. D-serme is synthesized by serine racemase, a brain enriched e.nzyme converting Lto Dserine. Degradation. of D-serine is achieved tiy D-amino acid oxidase, but this enzyme is not present in forebrain .areas that are highly enriched in D-se.rme. We now .report that serine racemase is a b.ifunctional enzyme_ catalyzing both the racemization and fN,fO-elimination ot water from s.erin% producing _both D-s_erme and pyruvate. We found that elifnination oi water from D-serihe provides a novel mechanism for regulating intracellular D-serine levels. Robust degradation_of D:serine by serine racemase was observed m. transtected HEK293 cells and primary, a.strocyte cultures. In. order to further investigate the role of elimin.ation in regulating cellular D-serine, we generated several serine racemase mutants display-ing selective impairment of elimination activity. As a result, levels of Dserme synthesized by the mutants are several fold higher _than the wild-type both in vitro and in vivo. Extracell-ular l)-serine is more stable toward elimination, likely due to p.h.ysieal separation from serine racemase and its elimination activity. Elimination provides a novel mechanism for tle metabolism of D-serine in brain areas lacking D-amino acid oxidase, with inaplication for the regulation of NMDA receptor neurotransrmssion.
Cannabinoid receptors and "failure to thrive" in newborn mice Fride E..1'2, Arshavsky N.1, Ezra D. lept, of Behavioral Sciences, College of Judea and Samaria, Ariel, Israel; 2Dept. of Molecular Biology, College of Judea and Samaria, Ariel, Israel; We have previously suggested that a deficiency of cannabinoid CB1 receptors may underlie the eni_gmatic syndrome in infants 'Non-organic failure to thrive' (NOFTT). Thus we have reportel that specific blockade of the CB1 receptors in one-day old mouse pups induced hypothermia, depressed ultrasonic vocalizations, prevented milk intake and resulted in death within days after birth. Similar deficiencies were found in (untreated) CB1-/knockout pups. Aim: To further evaluate the validity and explore the mechanisms of neonatal CB receptor blockade as a model for NOFTT. Procedure: We compared the effects of neonatal blockade of CB1 receptors (with SR141716) in two strains of mice (ICR and Sabra). Experiment 1: Suckling-related motivation, general motor befiavior and pro-motor performance were studied in pups, when exposed to an anesthetized dam. In addition daily measurements were made of body weight, ulasonic Localizations and axillary temperature. Experiment 2: Sontrol and SR141716-treated pups were warmed to 300C and developmental parameters were measured as before. Results: 1. ICR mice display_ed more competent suckling than Sabra's 2. The rate of mortality induced by CB1 receptor blockade is strain-dependent 3. General motor and.
pro-motor behaviors are suppressed in SRl41716-treated UpS but motivation to suckle was not impaired 4. creasing environmental temperature prevented hypotherfnia in the experimental pups, but did not prevent the suckling impairment and mortality induced by CB1 receptor blockade. Conclusions: CB1 receptors play a critical role in the ability_ of newborn mice to suckle milk, but genetic differences determine the rate of vulnerability Conclusi,ve _evidence for the existence of a speci.fic receptor for delta-9-tetrahydrocarmabinol (THC) the rnajor psychoactive constituent of marihuana, ws obtained in 1.988. Since then this receptor has been cloned and detected in widespread areas, in the b.rain, highly concentrated in the niostriatal system, hippocampus, cerebral cortex and cerebellum. A second receptor was cloned in 1993 in Re. rip.heral tissue, and found notably on. immun.e cells, but hlso in embryo.nal cells, o.steoblasts and osteoclasts. The centrally located receptor detected in the brain was denoted "CBI" and is mainly found presyq.aptically where it modulates transmitter release. The "peripheral" ree.eptor is called "CB2"; both are G-proteincoupled. Since tliese discoveries, CB1 reee.ptors have been detected in many localities outside the 15rain, including sympathetic ganglia, immune cells .and the astrointestina-I system. Recent evidence indicates that CB2 receptors are also expressed in glial cells in the brain and have even been suggesfed as neuronal receptors. Phylogenetic.ally, CB.1 receptors are already, present m primitive ivertetrates such as Ieech and Hya. Ontogenetically CB1 and CB2 receptors are present from the emb.ryn'al,preimplantation stages. In yiew of their widespread distribution, it is not surprising that cannabinoid rec.e.ptors and their endogenous ligands tide "endocannabinoids" fulfill mao.y functaons in ILtiysiolo,gical as well as in paophysiological conditions. lheir tunctions include t'eeding and appetite, pain perception, motor /unctions, blord pressure regulation, bone remodeling, memgry and regulation of tlie stress response. Pharmacological data laave sugges.te_d the existence of additional CB receptors which await detinitive identification. Research of fide "Endocannabinoid-CB-Receptor System" has greatly accelerated over the lst decad..e. OISservation,s ensuing from these efforts xill contribute to our understanding of this newly discovered highly important biological system.
Variability of the mesolimbic neuronal activity in a rat model of depression. The Flinders Sensitive Line of rats is a widely accepted and validated model of depression. These rats demonstrate abnormalities in limbc dopamine neurotransmission, suggesting disturbed neuronal activity in the ventral tegmental area. Interspike interval time-series were.. recorded from the ventral tegmental area of control Sprague-Dawley and Flinder sensitive line rats. These data were analyzed for the variance of interspike-interval for each group of animals. We found that FSL rats show a significant decrease of the variance of interspike intervals ot the length 0.2-0.6 sec. We suggest that fide interspike intervals of this range have an m.portant role in the information encoding in the mesohmbic dopaminergic System. Impaired varence of the interspike interval lengtl. in this area can correspond to the pathophysiology of depression and can be a possible marker for e analysis of the efficiency of antidepressant treatment. Using live fluorescence imaging we studied .DOC2B dependence on Ca+2 and founl that DOC_2 translocate to th6 membrane at very low internal Ca+2 concentrations (-200riM) and presents a positive correlation between the internal Ca+2 concentrations and translocation. Mutation in the C2A domain that affected the Ca+2 bindin site caused the lrotein to be constantly_ on the plasma membrane. Using. flash photolysis of eaged-C.alcium, we studied e effect ot-D.O.C2B on the different kinetic components of ex0cvtosis with c.apacitance measurements: Over.xpres.ion of DOC2B caused an increase in the fast burst size and a decrease in the sustained c.omponent..We also tested the ohysiolqgy relevance of the mutated C2A domain and t'ofmd that overexpression of the mutated DOC2B caused an increase in all 3 kinetic components of the exocytosis response, in the first and the second .flash. These results s.uggest that DOC2 is a positive regulator or exocytosis an.d ifflue.nce ex.ocytosis vi.a time-dependent interaction with another prmung protein.
Latent inhibition in schizophrenia: two poles of abnormality al G., Biran L., Mendlovic S., Levkovitz Y. ta Mental Health Center; When a relatively simple stimulus such as a tone or visual shape is repeattdly presented as irrelevant, it becomes difficult for that stimulus to enter into new associations. This phenomenon, termed latent inhibition (LI), is extenslvety studied in animals and humans reflects the ganism's capacity to ignore irrelevant stmauli..In the clfi,,ical setting LI the results of LI studies indicate tlaat it is disrupted during the initial stage of schizophrenia, or during an acute phase of a relapse. Thus LI dis..rupt.ion is_ considered to model the main cognitive attribution .schi.zophrenia patients, namely, inability to igngre irrelevant stimuli. Based on data from animal studies Weiner (2003) proposed the 'two-headed' model of LI, pointing that the LI phenomenon could represent two e..xtrem.es which charateri.ze schizop.hrenia patients, the disrt]ption of LI in the initial stages, and a perststence of LI in chronic patients. We have recently developed a new within-subject LI predure which s based on visual recognition of letter characters. A special feature of this procure is that it enable the testing of the two abnormal .poles of the LI phenomenon in a single testing ses.sion.
Application of th6 procedure in schizophrenia patients have confirmed the hypothesis. First, healthy volunteers have shown faster learning of the pedictive value of novel compared to preexposd cues, dicating LI. In addition, in.
healthy subjeet_s th LI effect as attenuated 4th repeated presentation or-the cues. Second, firstrepisode phtients learned the predictive values of novel and pmex .ed cues in a similar rate, i.e. LI disruption. Third, Chroriie patients have shown faster learning the predictive value o-f novel compared to preexposed cues, and this effect was not attenuated with repeated presentation of the cues, namely, LI perseveration. These fihdings are the, first demonstratign of e applicability of the 'two-headed model of LI to the clinic.

Identification of regulatory mutations in the MECP2
gene associated with Rett Syndrome by means of quantitative RNA expression assays in peripheral blood. Gak E. ,, Petel-Galil Y.., Vecsler M. ., Ben Zeev B.
Additional 10% of the pattents have been found to harbor minor or major deletions involving MECP2. In attempt to verify the role of MECP2 as a single underlying cause of RTT, we pursed the detection of additional mutations in regulatory, elements of MECP2 in clinically definite RTT cases. To this end, we employed quantitative RNA expression assays in the peripheral blood lymphocytes including TaqMan probes for both known MEC.P.2 transcripts and RNAse-P and ODC reference genes. Within this framework, we identified several patients with lower blood MECP2 expression levels that had no previous_ indications of MECP2 mutation presence. By means of denatured-high-performance-liquid-chromatogrhphy (DHPLC) and dtrect sequencing of the non-coding MECP2 regions, we identified a novel splice site mutation in the first exon-intron junction of MECP2 that potentially leads to imbalance between the two MECP2 transcripts. We also detected several potentially meaningful elements in the intron adjacent to the alternatively spliced exon 2 of MECP2 and in the 3'UTR. These "elements were highly conserved among species and were associated with RNA splicing or RNA transcription machinery in other genes.
We also obtained a preliminary in.,dication of overexpression of blood MECP2 in patients ith missense mutations, which overlaps with recent findings in a controlled mouse animal model that traced overexpression of MECP2 to a neurodevelomental delay ptienotype reminiscent of RTT.
Novel Bifunctional Drugs with Ir0n-Chelati_'ng .and '--'e-Apfand USA NPF Centers of Excellence, Technion-Faculty OfMedicine, _lpt. of Ph_armacology; The Weizmann Institute of ,:ience, Rehovot; One of the defming characteristics of neurodegeneratie diseases, including Parkinson's disease (PD), Al-zheimer s disease and arnyotrophic lateral sclerosis is the abnormal accumulation of iron in the affected brain areas, which together with monoamine oxidase (MAt) contribute to the onset of oxidative stress ia generation of reactive hydroxyl radical. We have developed several bifunctional iron chelators from the brain permeable iron chelator VK-28, possessing the nettroprotective propargyl-MAO inhibitory moiety ofrasagiline. The bifunctional dirug, M30, has been shown to be a potent iron chelator, with an IC50 value (9.211M) comparable to that of the prototype iron chelator, desferal. It is also a potent inhibitor of bryan mitochondrial MAO-A and B m-vitro (IC50A 0.041aM, IC50B 0.05IaM). In-vivo, M30 markedly inhibits brain (striatum, hippocampus and cerebellum) IIAO-A and B activities, wtth a greater selectivity (20-30%) for the latter at the doses (1, 2.5, 5mg/kg) examined. It has very little effect on the liver and small intestine enzymes, These results indicate that M30 has the ability to penetrate the blood brain barrier, and suggest that similar to,Iadostigil it would not induce the cheese reactton m response to tyramme. Important y, M30 attenuates striatal d0pamine depletion induced by tlie oarkinsonian neurotoxm N-methyl-4-0henyl-1,2,3,6t'etrahy&opyridine (MPTP) in mice and fiacreases brain levels of dpp.amine, serotonin and noradrenaline. M30's ability to inhibit MAt and chelate iron, may have a great potential as a neuroprotective drug as eompared to its. individual components, since, recent studies have indicated that a combinfitions of two drugs were more effective in preventing neurodegeneration. A9 important coggitive feature of adaptive emotion is its relatedness to abject, wheth.e.r a physical object, a person or an event (i.e. intentionality). Does p.ocessin this _cognitive aspect of _e. motion invtlve the li/nbic networks? Isolating inlentionality in emotion is not p.ossibl.e with standard p.aradigr..s in which the emotion is directed to the stimulus ihat is eliciting it. To address this issue we used a ero.ss modal apprqa.ch to evoke similar emotions with and without intentmnality content. In an fMRI experiment, 15 healthy su.bjects .(F=8) were scanned in a 3T GE sy_tem w.hile passively li.steng to emotional musical elip_s. Each clip was presented tice for 21 see: once combin&l wi a neutral film in the first 9see (Film+), .ao.d once without the film (Film-). We assumed that music elicits an emotion .ngt r.elating to an object; however, the film orovides this abstract .emotion ith meaningful reference (i.e. inl:.entiona.lity). The musical clips were of negative, positive or neutral emotional valence and the films neutral, as validated in a preminar, behavioral study (n=15 p.<10E-6.). The .addition or neutral film to th.e music did h-dt elaange the rated prgperties ofthe emotion e.licited.. The last 6 sec bf Film+ d Film-(featuring identical stimuli) were contrasted in order to fred"film traces in the musical emotion. Prefrontal regions were_ activated in bg_th emotional _and neutral conditions. No emotion-speeitie activations tor traces were found in the _a:0a_yg.dala. Film traces in negative music evoked the sub-callosal eingr4.1ate and rigl..t superior te.mporal suleus (STS) while in p.ts.itive .music they evoked the.left STS.. This study was able to demonstrate differential cortical activation to cognitive traces in emotional experience. Clotiapin is a neuroleptic with chemical structure similar to clozapine. Probably the patients unresponsive to other neuroleptics respond to clotiapin. However after the discovery of D-2 blockade as a mechanism of neuroleptic efficacy, this claim seemed to lack logical theoretical basis. The success of clozapine in patients unresponsive to other dopamine blockers raised hopes for the discovery of new antipsychotic drugs with new mechanisms of action. Thus the authors became interested in the fact that 40 patients in our 454 bed hospital were being treated with clotiapin and the treating physicians felt that this drug has unique antipsychotic properties in neuroleptic non-responsive patients. The Lokshin et al study' (1998) suggested that clotiapin may indeed have unique properties. Clotiapin affects multiple receptors like clozapine and olanzapine. It blocks 5HT3receptors and down-regulates cortical 5HT2receptors like clozapine. The ratio of D2 to 5HT2 blockade by clotiapin is similar to that of clozapine. Clotiapin and clozapine share high aff'mity for the 5HT-6 receptor. Clotiapin shows little blockade of D-2 receptors and in the rat retinal model seems to possess D-4 blockade like clozapine, although D-4 blockade by clotiapin has not to our knowledge been evaluated directly. We are conducting a study of severe chronic active psychotic hospitalized patients with a history of non-response to at least 3 neuroleptics. The design is double-blind crossover of clotiapin vs. chlorpromazine (CPZ) as monotherapy. No washout is necessary from previous neuroleptic treatment, and flexible overlap over 2 weeks with the study medication is individualized for each patient. Patients are treated for 12 weeks with clotiapin and 12 weeks with CPZ, in random order. Medication is supplied in identical capsules of 100 mg CPZ or 40 mg of clotiapin. PANSS and Nurse's Observation Scale are rated every 2 weeks. 38 patients have completed the trial. Initial results are presented.

Wemannlnstitute of Science;
Depression is among the most prevalent forms of mental illness, but the neurobiologieal basis of depressive behavior is poorly understood. Many of the roi:len.t models for depression are based on the assumption that depression is a response to acute or chronic stress. Other models are based on assumption of a certain biochemical dysfunction that underlies depression, while there is no consensus on the biochemicalbasis of depression. The diagnostic criteria for depression include several s_35nptoms and it has also become clear that the risk t'or depression is partially genetic. We were therefore encouraged_ to in,estigate genetic factors of depressive behavior by establishing a novel animal model for depression based on selective breeding for a depressive pheno_type. The selective br.eedin& is based on tests that cover the core symptoms: loss ot interest or lack of motivation (using a mbdified sa4mming tes0, anhedonia (using the sucrose preference test) and reduced chert/fatigue by chronically screening locomotor aetiv!ty (lnfmmot system). Additionally, we have d.evelo.ped a novel scoi-ing method of the swimming test, that allow continues momtoring of different levels bf the animal's activity, using a jgystiek. This novel method shows a Gaussian distiibutitn of scores (which is not observed in the standard scoring method) that is necessaoy_ for reliable selection of extreme cases for the purpose of our selective breeding. We found already, at tlie decond g.enation of descend-ants a sgnificant differences between "depressed" and "motivated" rats in the swimming test, in the basal locomotor activity at young ages and in offsprigg quantity.
At this point we fred no correlation between th different tests. We expect this model to allow the s.tudy ofthe genetic contribution to depressive and motivated bthavior mad the neuroehemieal ehaeterization ofthese behaviors.

Dept. of Physiology & Pharmacology, SacklerMedical
School TelAviv University The KCNQ potassium channels whose mutations cause cardiovascular and neurological disorders are members of the SUlerfamily of voltage-gated K+ channels. The KCNQ1 pore-forming subunit can interact with various KCNE auxiliary subunits to form K+ channels with very different_ gating behaviors. Inactivation gating is a property of KCNQ1 that is susc_eptible to modulation. KCNQ. inactivation is invisible macroscopically but can be revealed by a hook of the tail currents which reflects recovery, from inactivation. However, KCNQ1 mutants can depart ihto a macroscopic inactivation mode. Here we show that in a long QT mutant of KCN.Q1, L273F, two distinct inactivation states coexist, one similar to WT channels and a macroscopic inactivation whose time course and recovery are much slower compared to wild type channels. inactivation produced by WT KCNQ1 is intrinsically voltage-independent, while that elicited by L273F is highly voltage-depeirl.ent. Interestingly, the two discrete inacttvation plaenotypes exhibit distinct pore prppertie_s.
External protons trp_ngly depressed WT KCNQ1 inactivation but weakl affected the macroscopic inactivation of L273F mutant. Similarly, external barifam ions discriminate between the two discrete inactivation states by suppressing the wild-type and barely affecting the maerosc0pie one. Allowing L273F channels to populate the voltage-dependent inactivation transition, prtdueed a consilerable delay in the exit of barium ions from the pore (more than 6-fold). This result suggests that during the voltage-dependent inactivation transition, the topology of the external vestibule is such that it tra barium ions reside the deep pore. A kinetic model of the LQT channel mutant accounts for the coexistence of two distinct inactivation states.

20
Conducting STDP in dendrites. Gidon A.A.', Segev I. qnStitute for Life Science, Hebrew University, Jerusalem; qnterdiscipfinary Center for Neural Computation, Hebrew University, Jerusalem; Spike timing dependent plasticity (STDP) is a synaPtic learning rule operating in many neuron types. When the pre-synaptie neuron fn:es after the post-synaptie neuron the. synapse is depressed whereas the synapse is potentiated when the_pre-synap_tie neuron fwes before the p6st-synaptie neuron. Ire time window for this plasticity, rule spans over tens of milliseconds and its dynamics vai'ies according to neuron type. We applied STDP learning rule in a dendritic neuron iriodel, using NEURON simulation environment. Random asynchronous synaptie inputs "_unping_ed onto the model neuron with initially imiforfia peak conductance for all synapses. After nmn'.m.g the STDP rul.e, a. bimod.al synaltic conductance distribirdon was attained at me steady state. Some of the synapses obtained the maximfil conductance change whereas the conductance of the other synapses was close to zero. The proximal synapses were the _s'tr96g ones and the distal synapses were near "extinction".
IndeX, STDP imposes compe.ition ..amon_g synapses over the control of the postsynaptie spike. Thus, a positive feedback loop ensues and prokirnal synapses, which tend to evoke larger somatic EPSPs have a better chanee_.at generating spikes and become progrsively stronger. Ire opposite is true for distal synapses, which generate smaller somatic EPSPs. We propose_ several soluti6ns for "saving" distal dendritic synapses from extinction. First, we show that a multiplicattve (rather than linear) learning rule can equalize the local conductance for all dendritic _mfnapses. Second, we apply anti-STDP rule (Rumsey and Abbott, 2004) for gmax, the maximal conductance possible for each synapse. Consequently, the distribution of synaptic s_trengths at the soma is identical for all synapses, in_d_epen_dent on their dendritic locati,o,. We also explore the effect of active dendrites on "saving" distal synapses from extinction. Finally, we consider STDP rule in different dendrites morphologies. This fMRI study investigates the differences between a blocked and event-relat&t analysis in a cued target detection task, the so-called Posner paradigm, using a hybrid design. Validly and invalidly cued trials were presented intermingled-in different blocks containing 50, 75, or 100 percent valid trials. Four analyses were conducted: i) An event-related analysis comparing invalid and valid trials, ii) a blocked analys.is comparing blocks with 50 percent valid and invalid trials to blocks th 100 percent valid trials, iii) a blocked analysis detecting differences between block models when modelled as epochs or chains of events and iv) a blocked analysis that modelled blocks as chains of events to scale regressors equally to the event-related analysis..19"espective of the type of analysis (blocked or event-related), significant activation of the right intraparietal sulcus was observed. A larger cluster size was evident in the blocked analysis which can be attributed to h.igher, efficiency. In additioia to Sharp (sub-exemplar) tuning for faces revealed in human face related areas Gilaie-Dotan S., Malach R.
Dept. of Neurobiology, Weizmann .Institute of Science,

Rehovot 76100, Israel
Although human face recognition is extremely selective, it is still un-clear how this selectivity is implemented at the neuronal level in human face-related cortical areas. In order to answer this question, we used the paradigm of functional magnetic resonance adaptation (fMR-A'). Our stimuli consisted of colored face photographs (neutral expression, male, Caucasian) which were parametrically morphed to produce various degrees of facial similarity. The face stimuli were divided into four groups: (a) identical images (no variability); (b) different face images (maximum variability); (c) 1/3morph faces, i.e., images morphed at 1/3 of the morphing distance from the full identical-to-different distance (low variability), and (d) 2/3morph same procedure but morphed at 2/3 of the morphmg distance (intermediate-to-high variability). Twelve subjects participated in a short block-design fMR-adaptation experiment and were scanned in a GE 1.5 T magnet. In order to balance task difficulty-between the identical and 1/3morph conditions, a 1-back memory task was used. Examination of the activation levels of the face selective fusiform gyrus (FFA) revealed that even small facial variability-(created by a slight morphing level of individual faces, 1/3morph condition) was sufficient to induce full recovery from adaptation (1/3morph activation vs. identical-face activation (p<3* 10-4), but 1/3mo_rph activation vs. different-face activation (p>0.07)). Our results demonstrate that face-selective regions are tightly tuned even to subtle shape changes at the sub-exemplar level. Such sharp tuning can provide the necessary neuronal sensitivity to allow highly selective face recognition. Dept. ofA;Iath, Technion, Haifa; History dependent time scales are a ubiquitous feature of neuronal systems, at all levels of orgamzation. It is not clear, however, how multiple time-scale dynamics rise from one level to the next higher one. This study approaches this question by looking at the interaction between the rich channel dynamics and the dynamics of neuronal activity; we construct a single neuron model in the spirit of single channels models. The model neuron describes its activity in response to an external stimulus. The activity is a coarse grained time-averaged representative of firing and temporal details at the resolution of action potentials are intentionally neglected. Novelly, our model input/output function s nonlinear, parametrically depending on the neural excitability. Changes of this ftmction on long time scales has been observed experimentally, but has been neglected in other neuron models. The model neuron is composed of ensemble of ion channels that can wander in a large pool or inactive states, and their distribution registers thehistory of activity. The concept of neuronal excitability is used to bridge the gap between dynamics of the channels and that of ihe neuron: channel kinetics modulates neuronal excitability, thus affecting the neural activity; activity, in ram, enhances channel inactivation. Thus, the neural activity is both affected bv excitability and determines the changes in it. In this way [he multiple time scale dynamics on the channel level rise up to the next higher level, which is the neuronal dyna.mies. In spite of its sim.plicity e model presents a rich repertoire behavior, with multiple time-scales dynamic. Moreover, the characteristic time scales of our model are histo.ry and context dependent.
These results are in quahtative agreement with experimental results. It is important to note the robustness of-these results, since no specific structure of the ion channel state space is required. Conventionally it is assumed that attentive visual perception of dentical stimuli engages the same perceptual mechanisms. However, attentive perception can engage at least two mental states: a. An internal, introspective statein which the subject attends both to external stimuli and to himself as an observing agent, b. An external, extroceptive state in which the su6ject is exclusively engaged by the external stimuli. Here we report on brain imagmg results which e.xp.lored to what extent these two mental states engage different cortical regions, despite being driven by identical sensory, stimuli. Five subjects performed two different tasks during a block-design scan. In a categorization task, subjects were required to categprize pictures (animal vs othe0. In the introspection task, subject were asked to look at the same pictures as in the first ta.sk but to attend at the same time to himself and evaluate his emotional reaction to the pictures (negative/positive vs neutral). Prior to each block, a visual cue indicated which task to perform and subject's responses were recorded. In order to discriminate task difficulty as potential confound between the 2 cognitive tasks, external categorization epochs were subdivided into "difficult" and "easy" perceptual tasks by manipulating presentation speed; "easy" epoclis were identical to the introspection task, stimuluswise. Our results show preferental activations across prefrontal cortex during "retrospection" compared to the "easy categorization" task. Consistent preferential activations were found bilaterally in dorsolateral and medial aspects of prefrontal cortex, with a left hemisphere bias dorsally. The results and their relevance to broader issues such as the search for neural correlates of subjective awareness will be discussed.
Funded by ISF center of excellence grant and the Benoziyo center.

New York
Recently (Hasson et al., 2004) we found that a .1.arge expao.se ofhu.man c9.rtex shows a higl, level, of inter-subject_ correlation when subjects are exl3osed to a long segment an audio-visual movte. While this finding reveals a wide spread level of.stimulus-driven activity in th.e human cortex, it was also noticed that certain cortical regions cons.iste.ntly fail to show such inter-subject correlation..-.This result hints that either these regions are related to .m.dividually unique cognitiv.e processes or_their activity, is dissociated from the external stimulation. To examine this issue.further, we mapped the. cortical areas showing high correlation between rel3eated pre.sentations of.the same movie in each individual. Our results Show that these areas stil.1 failed, to. show y movie-driven correlations.indicat',mg that their activit is intrin.sic and unrelated to. e external sensory stimuli. Functional connectivity anal.y.sts of these "intrinsically" driven areas revealed a result all the. coical re.gions in e caudal brain whieIi were un-correlated to the external stimuli showed an intrinsic correlation with each otherforming a. closely interlinked network. Furthermore, the two networks i.e. the externally driven system of sensory areas and the intrins.ically driven network complemented each other providing essentially complete coverage of the entire exten.t bf th.e human caudalbrain. A large nuiber of expg.riental. results in our lab and in the pulSlished literature indicated that the "intrinsic" system largely overlap.s with a set of regions previously shown to be de-activat by .any senso sttmulus. Thus,.we ould like to propose a furidamental neuroanatomical 1)artition of the htirnan caudal brain into two global networks of areas: those dealing with processing external sensory input, and .those dealing with some, as yet not fully understood, internal cognitive tunction.  Nature, 2000). In contrast, the latency of the response of neurons in VPM thalamus is essentially constant. Yet the two nuclei are inhibited b}_, an overl_appmg region of reticular th_alam,ic nucleus (RE). To provide a possible explanation tor this Zinc Modulation of the L-type Calcium Channels. Goshen U., Baharir O., Moran A.
--Dept., Faculty_ ofH(alth Sciences, Ben-Gnrion Univervity of the Negev, Beer Sheva.; Zinc modulation of the L-type Calcium channels (LTCC) was studied in Xenopus oocytes expressing alpha l, alpha2 delta and beta2 subunits of the rabbit cardiac calcium channel. Whole cell voltage clamp experiments were carried out using Ba2+ as the charge carrier. Our results show that zinc causes a reversible inhibition of LTCC in a concentration dependent manner. Nonlinear fitting to a Michaelis Menten equation yielded an appKi of 102 micromolars and a Hill coefficient-l. The decrease in steady-state current amplitude is accompanied by a shift of the I-V relationship to more negative voltages. Similar inhibitory effect of zinc was found in the presence of the LTCC activator BayK 8644. In contrast to the inhibitory effect of extracellular zinc, no such inhibition is observed when zinc is applied intracellularly. The injection of of zinc (-80 micro molars) changed the extent and rate of current block caused by extra-cellular zinc. Hence, we concluded that intracellular zinc although did not block LTCC, was capable of modulatang other cellular functions. Zinc inhibition of LTCC developed with time, reaching maximum inhibition after 3 minutes. The inhibition was not activity dependent as similar inhibitory effect was observed when oocytes were either exposed to zinc and activated. every 10 second or exposed to zinc with no stimulation and tested after 3 min Our results suggest that zinc may,.play an important modulatory role of LTCC in physi,61ogical concentrations. Zinc inhibits the channel's currents by acting from the extra-cellular side and its effect is not actiwty dependent.

NAP (ALl_O_): A Peptide Derived From Activity-Dependent Neuroprotective Protein (ADNP) is Poised Toward Clinical Development
Gozes I. 1Clini-al Biochem. Sackler Med. Sch., Tel Aviv Univ. 69978, Israel; Activi.ty-dependent _neuroprotective protein (ADNP) is essential frr brain tOrmation (Dev Brairt Res. 2003 144, 83). Peptide activiW scanning identified AP (NAPVSIPQ a.lso kalo'.n as AL 108) as .a small actiye tragment of ADN_P that provides neuroprotecton at very low concentrations. In cell culture, protection has been demonstrated agast toxicity associ.ated with the b.eta amyloid pep.tide,. exeitotoxicity, electrical blockade, the envelope protein the AIDS virus, dooamine, H202 nutrient starvation and zinc intoxication (JBC 2004, 279,'28531" JPET 2004309 1190. In animal models of alaolipoproin E deficiency cholinergic to.xicity, closed headinj.u, stroke, middle aged anxiety and cognitive dysfunction, NAP orovifled neurolrotection (N-eurosci Lett. 2004, 361,128;JMN 2004 24 181). The structure of N.AP allo.ws cell penetration iibition oI-toxic protein beta sheet IOrmation and stimulation 9f p.roper protein assembly. NAP binds to tubulin and tacilitates microtubule polymerization l.eadi.ng to enhanced cellular survival that is associated witti fundamental brain cell elements, the cvtoskeleton. A mass spectrometry assay determined that NAP reaches the brain up.on nasal administration showing a half-life of 90-120 minutes in rat and dog plasma. In a batteoi-toxicological Results from the first fully analyzed brains (N=5, normal, 4 suspected pathologies, 25-33 weeks gestation) indicate that ventricular enlargement and asymmetry in this sample result in a proportional increase and_'_dsymrfietry in the total he.rnispheric volume, with no effect on.. parenchyrnat volume asymmetry. However, the contribt/tion of the ventricular volume to the total hemisphere volume gave a faithful representation of the severity of the ventiScular enlargement, regardless of gestational age and absolute hemispheric or ventricular volume: the lateral ventricles represented '2% of the total hemisphere volume in the normal fetus and 4.7-38.9% in the pathological brains. These preliminary, results support the use of image analysis. and MRI to produce quantitative severity assessments brain pathologies in the developing human fetus. An approach to the molecular basis of tinnitus in the rat G__uittonM., Dudai Y.
elot, ofN__robiolog3? The Weizmann Institute of Science, vot 76100, lsraeI; Tinnitus is persistent and debilitating ringing in the ear. It is very common in the adult population. Little is known, however, about the molecular arid cellular mechanisms that underlie this pathology,,. The understanding of these mechanisms could lead to the development of new theraPeutic stratees. Further, the analyss of long-term tinnitus could unveil molecular and cellular mechanisms of persistent experience-dependent alterations in brain circuits that subserve sensory, emotional, and cognitive responses. Toward that end, we have develgped a new beliavioral paradigm to study tinnitus in the rat. Animals were conditioned to locate a platform, submerged in one of two arms of a water T-maze. The arm in whicli the platform was located depended on the presence or the absence of a.tone which was chosen to mmie, salicylateor noise-induced tinnitus. The rat had to learn to associate the tone or its absence with the platform-containing arm. Conditioni.'ng (three 15-20 min sessions of 12 trials each) led to a marked increase in the prob.abil.ity of coect arm choice in response to the presence or the absence of the tone, and a decrease in time to reach the platform. Memory of the tone-or no-tonearm association was evident 15 days atter training. Titmitus was induced by sodium salicylate (300 mg/kg/daf i.p. for 4 days) or by over-ex.posure to noise (6 kHz 130 dB SPL, 15 mm). The expectation was that animals wth tinnitus would behave as th6ugh they hear a tone even in its absence. This indeed was proven to be the case: treated animals spent significantly more time in the arm associated with the tone even in silent periods. This protocol hence permits objective measure of tinnitus in the freely moving rat.
Combined with inner-ear targeted or brain targeted pharmacology, it could facilitate the investigation ol" the molecular mechanisms of tinnitus. Preliminary results unveiled similarities of molecular mechanisms of tirmitus and neural plasticity and memory.
Anxiety associates with taste to produce conditioned taste aversion in the rat of Neurobiology, The gYeizmann Institute of Science, Rehovot 76100, Israel; The interaction among experience, emotion and memory is. considered to be instrumental in the ontoge_ny maintenance of acquired emotional and behavioral disorders, e.g. phobias. Here were address the question whether anxiety can associate with taste to produce conditioned taste aversion (CTA). We have used an anxiogenic agent, the 5-HT2C receptor agonist metachlorophenylpperazine (mCPP)., to induce afixiety in rats after consumptton of an unfamdiar tastant. The arxiogenie agent induced CTA. The mCPP-induced CTA could be prevented by concomitant adnfinistration of ethanol, which s known to reverse mCPP-induced anxiety, at a concentration that had no effect on CTA memory__. Ethanol did not prevent, however, LiCl-induceit CTA. Administration of mCPP before the consumption of the .We investigated human category learning from partial information provided, b equivalence, cons_ti'.ain.ts. Fart..i.eipants learned to el.assily stirriuli on the b.asis 9r ei.ther pQsitive .or. negative eqmv.alen.ce, constra'.mts, that m, when mtorme..dthat two exemplars belong to the same category or to .ditlerent categories, respectively. Knowing that. iia n.atural contexts positive constraints are more informative than negative, constraints, we_ suspected that p.a.r.t.icipants will not use the two types ot constraints in sihailar w.ays .even in a se.tng in which_ the amount ,of objective information in the two types or constraints is identical. We discovered that when orovided with positive cons.aints, particioant categorization performance is distril)uted normally, but wh.en providdd with negative constraints. Expel. object recogni.'_tion occurs when one learns through experience to identify quickly and accurately individual exemplars of a homogenous class, a process associated with quah.tative ch.anges in perceptual processing. The neural meelaanisms that underlie the perceptual changes, however, are not sufficiently elaborated. Recent resear.eh to date, investigated expertise as an alternative to the putative domain-specificity of face processing (MeKone and Kanwisher, in press). Thus, neuroimhging studies of expertise were limited to face-selective ROIs bf the ventral visual pathway. But, selectivity for objects of expertise may not involve only face regions but may manifest as an organizational pi'ineiple in ventral visual-pathway, starting as early as retinotgpic areas. In the present study we examined this hyp0._thisis. Five car experts and five novices were presented with three object categories: ears, airplanes and fhees, while being scanned in a 1.5T MRI scanner. A one-back memory task was performed by all subjects. Differential BOLD-fMRI responses were found in car experts, in response to ears compared to ear novices while e_q-uivalent response.s were fo.ud to f_aces and "mrplan.es..
:Since cars and airplanes are objects of tr.ansportatio.n wtla ap_proxir.ately e.qu_al level of visual complexaty, in absence o..I expertise no difference should have been .expected in the distribution and level of brain activation elielted by each object category. Our preliminary results s.uggest that differential responses to ears can apl_.ar in various regions of the ventral visual pathway in kldition to the fusiform face area, including lateral occipital areas and posrior ventral temporal areas. We conclude that expert object recoggition modulates visual peree.ption, and hi.'s moditla,fion may be reflected by neural selectivity in the experts visual cortex for objects oftheir expertise.
Neuroprotective potency of the iipophilic transition metal modulatorDP-b99 against oxidative stress Hating R,, gesnitzky D., gudich H., Gileadi C., Schatz G., Striem S., Angel I., Kozak A., Friedman JE. D-Pharm Ltd., Rehovot 76123, Israel; Reduction in glucose and oxygen supply, which oe.e.urs in cerebral ischefiaia, leads to a cascade 6f events resulting in neuronal death. We have synthesized a lipg.philie analog of BAPTA, DP-b99, currently in Phase II eliiaical trials, knd determined its neuroprotective potency. We have reported that following MCAO in rats DP-b99 was found to reduce infarct volume and improve neurological scores. Here we present results from several in vitro studies using different models of oxidative stress. Oxygen-glucose deprived (OGD) hippoeampal slice cultures were ffsed as a model of ischemia. OGD was induced for hr followed by reperfusion. Cell death was quantified by measuring LDH release and the cellular uptake of PI. LDHrelease increased gradually over the 24h period following r_eperf_usion. PI uptake increased mainly m the CA1 region but also in the CA3 and dentate gyrus following OGD. DP-b99 (30mM) reduced significantl both LDH release and PI uptake at all time points tested. Exposure of cortical neurons to 100mM H202 for 4h causes oxidative cell death. Pretreatment with DP-b99 or BAPTA-AM signifieanflyprotected the cells. The NMDA receptor antagonist MK801 and calpain inhibitor MDL28170 also protected against cell death. Calpain activity in H202-treated neurons and OGD-treated slices was determined by evaluating p.roteolysis of the calpain substrate a-eclxin. DP-b99 inhibited H202-induced calpain activity, suggesting that DP-b99 may.
protect,in part, through calpain nhibRion. We further useit ihe HT22 hippocarnpal cell line that lacks ionotropic glutamate receptors but is sensitive to gluta.mate-indueed death via oxidative stress. DP-b99 protected the cells by 50% when added before or up to 4hr after glutamate. Taken together, the neuroprotectave potential of DPz_b99 in isehemie rat models is related to its protective etlect in different types of neuronal cultures demonstrating its usefulness in the treatment of cerebral ischemia. Supported by D-Pharm Ltd.

26
Fast-Same effect: implicit priming of ordinal number categories Haroush K.', Orlov T.', Hochstein S. ',2 'Dept. ofNeurobiology, Silberman Institute ofLife Sciences; qnterdisciplinary Center for Neural Computation, Hebrew University, Jerusalem, Israel; Humans and monkeys categorize images according to their ordinal position in a repeated list. Category assignment is assumed to be based on an abstract kibel (first, second, etc.), common to all images of the same ordinal catego_ry (Orlov et al., Nature 2000, Cerebral Cortex, 2002. In previous research with human subjects we measured explicit category priming. Subjects were trained with 32 images, divided nto 8 quadriaplets. On each trial they viewed 4 sequentially presentedsample stimuli, followed by a test stirhulus, consisting of the same 4 images. The task was to select the images (by mouse-click) in their correct order. Performance g!"_adually improved. A subsequent memory test corifirmed subject ordinal categorization of the stimuli. In a following priming test, we presented subjects with a prime image to which they responded by r.eporting covertly the image category. The.n (0.3-Is after pril:ne presentation-), they were presented with a pair of target images to which they reported whether the tgets belong to the same category or different categories. We found that explicit retrieval of the prime category shortens reaction time (RT) of the same-different judgment if the prime was of the same category as one or both of the Beyond the related endocrine and behavioral alterations fotind after maternal separation in various animal studies, the development of synaptie connections in limbie brain regions is modulatrd by early adverse emotional experiences, i.e..the separation from the parents (P_oeggel et al., 2003). In the present study the effect orchronic separation from the father on the development of dendritic sprees in the limbic system was analyzed..Quantitati_ve analysis revealed region-, cell and dendrite-specilte changes of spine densities in the orbitofrontal cortex, in the lateral and basomedial amygdala, hippocampal CA1 region and dentate gy_s of three week old .tnkmpet-tailed rats.-The compar_ison of pups which were either raised with or without their fafher revealed in the fatherless animals a 40% decreased spine density on apical and basal dendrites of layer II/IIIpyramidal neurons ih the orbitofrontal cortex and up to 20%lower apical and basal spine densities in the amygdala whereas the dendritic lengths remained unchanged. No changes of spine densities and dendritic lengths were observed in the hippocampal CA1 pyrami._dal neurons and in the granule cells of the dentate gyrus. fhe lack of paternal care appears to inhibit or suppress the formation of presumably excitatory_ spine synapses in the limbic cortex and in the amygdala, whereas syna_ptic develop.ment in the hip_pocampus occurs independent from paternal interaction wiili his offspring.
Supported by a grant of the state of Saxony-Anhalt. neutral faces presented to one eye, competing with a house presented to the other, were studied with and without their aware percept. 40 sec periods of fused stimuli (Rivalry) were fdllowed by same periods of distinct stimuli based on su.bject's response during the rivalry (Replay). 22 subjects indicated longer aware percept of faces than houses and more so for fearful faces (interaction, p<0.05), suggesting that fearful face biased the competition for enhancedvisual processing during BR. To stud_ the brain dynamic of this bi,as, high density MEG and fMRI were applied on 10 subjects. During aware fearful face more than neutral face, MEG showed increased power in beta (14-24Hz) and theta (4-8Hz) bands in estimated sources in the medial temporal sources (MedT) that include the amygdale and. However for switching from a house to a face more so for a fearful face, both MedT and inferior temporal (IT) regions showed increased power. These regions were also observed in the fMRI data when comparing rivalry vs. replay more so in the fear condition. Ths provides convergmg evidence for limbic-visual involvement in the dynamic aspect of competing visual processing of emotional stimulus. Next we apphed coherence analysis to the MEG signal timecourse obtained in the from MedT and IT sources during periods of switch to-and state ofaware or unaware faces. We found that coherence in the beta and theta bands respectivelv probed catego (face house) and emotional (fear nettral) aspects of the competition. This suggests that emotion mediates awareness through large scale coupling between visual and limbic regions. When people detect their errors in a discrimination task, a negative-going waveform can be observed in scalp recorded EEG that has been coined the error-relateit negativity (Ne/E.R:N). Although far less elaborated in the EI(P literature, a later oecurnng error positivit3 (Pe) also appears to be associated with response monitoring processes. Falkenstein et al (2000) proposed that the^P e may be related to additional processing that occurs atter error detection, such as conscious error recognition. In a pilot study we encouraged five participants to correct themselves in a two-choice reaction-time task. Surprisingly, participants tended to produce the same correct response twice (namely, produce a double correct response) as often as they tended to correct their errors. Reaction times of the second responses were found to be longer when they were a repetition of a correct response then when they were a true correction. Although a Pe-like component was found in both response types, the ERN-like co.mponent was found only in correction responses. These f'uidi_ngs support the conception of the Pe as associated with consciousnes awareness of the output of the monitoring process per se.
Depl of Ci/n. Biochem., Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel; Activity dependent neuroprotective lrotein (ADNP, human calculated molecular mass I23,562.8 Da) is a newly discovered glial lrotein that it is essential for emb.ry__oniiz develgpment and'brain formation (Pinhasov, .2003 intraperitoneally, significantly ameliorated the clinical severity of EAE reduced m mice by myelin oligodendrocyte glvcoprotein (MOG). Central nervous system (CNS) "inflammation and axonal degeneration were prevent .ed by this treatment. RhAFP also inliibited T-cell activity and antibody production and downregulated the expression of cell-surface leukocyt_e markers CD3, CD1 b, NIHC class II and CCR5. In addition we tested estrogens and dehydroepiandosterone (DHEA), (a neurosteroidand the precursor of steroid hormones), using an in vitro model-of CNS inflammation, and an encephalitogenic T-cell culture. 17estradiol and DHEA exerted a moderate inhibito effect on LPS-induced nitric oxide (NO) secretion. In addition, DHEA reduced MOGinduced T cell proliferation. Our observations show that several pregnancy-related proteins and hormones influence immune function and might be succegsful candidates alone or in combination, for therapy of autoimmune diseases. Current protocols to generate populations, enriched for a, distinct cell _type, most commonly rely on an initial spontaneous disorganized step of differentiation, co-culture, the use of undefined conditioned medium or factors with non-specific and/or poorly understood effect. Here we report the efficient, controlled, reproducible, single step conversion of hES cells into highly enriched cultures of developmentally competent proliferating neural precursors (NPs). When hES ceils are cultured in def'med serum-.free medium, in the presence of specific soluble factors they uniformly develop into highly enriched cultUres of NPs. We show that these culture conditions suppress non-neural differentiation and allow hES cells to adtpt a neural fate. The NPs may be propagated for prolonged periods, and can differentiate into astrocytes, oligodenckocytes and various subtypes of neurons including mature neurons that fire action potentials and form f-finctional synapses. During prolonged propagation of the NPs, a gradual shift from neuronal to predominantly glial fate s observed after induction of differentiation, probably reflecting the neuronal to glial developmental shift that occurs during neurogenesis in vivo. The presented controlled, single step conversion of hES cells into near homogenous cultures of NPs, is highly valuable for the study of human neurogenesis. It allows the efficient and simple creation of neural-cells for drug development and is an important step towards the potential utilization of hES cells in transplantation therapy of neurological disorders.
Abnormal K+ buffering in the epileptic blood brainbarrier disrupted cortex Ivens S. , Seiffert E.', Dreier JP.', Heinemann U. , The blood brain-barrier (BBB) is a comp.lex structure designed to maintain a unique neuronal environment and limit the penetrance of serum components to the brain. We have recently demonstrated that opening of the BBB leads to a delayed (4 days) appearance of a long-lasting focus of epileptifbrm activity. Ths was associated with early (24 hrs) activation of astrocytes. In the present study we investigated K+ buffering in neocorticalslices maintained in vitro. Extracellular recordings using ion,sensitive microelectrodes were done in treated and sham-operated cortices 1-30 days after surgery. K+ buffering was studied following tetamc and single pulse stimulation or K+ ionophoresis. In all cases buffering was found to be co._mpromised, strongest day after BBB-treatm.ent and full/recovered with 4 weel. To differentiate betvqeen different buffering mechanisms we applied low concentrations of BaCI (1001M) to the bith to block inward rectifier K+ channels (KIR). This was significantly less effective in augmenting K+ sig.als in the 24-hrs BBBdisrupted cortex. In contrast, fi/aher increase in BaCI (2mlVI) to block K+ leak currents was equally effective in_ control and treated cortex. Ouabain in concentrations or aajM which blocks predominantly_ the ot2/3 subunits of the K-ATPase had a smaller effect on the clearing of ex.t(.aeellular K+ in treated slices one day aflgr treatment, indicating a smaller activity_ of the enzyme. This compromised buffering showed functional significance as slow repetetive stimulation (0.33-0.67 Hz) evoked abnormalafterpotentials after the third and 5th stimulus of a tram only_ in treated cortex which were never seen after_ the first stimulus. Our results show that development epileptiform activity in BBB disrupted cortex is preceeded y activation of astrocytes and impaired K+ buffdring. This could contribute to neuronal hyperexcitability and later on to the development of chronic epilepsy.
The origin of Purkinje cell simple spikes and the role of parallel-fibers Jacobson G.,'-, Yarom Y..2 iDept, of Nqurobiol_ogy, Life Science Institute; '-The Interdisciplinary Center for Neural Computation, Hebrew University, Jerusalem; Purkinje cells can disp,lay two different suprathreshold responses: complex spikes and simple spikes. Complex spikes occur wlien the climbing fiber input onto a Purl.inje cell is activated, while simple spikes are considered to result from granule cell inputs. Recent results raise two questions concerning ".he simple spike activity of Purkinje cells: 1) Do simple spikes represent_intrinsicproperties of Purkinje cells or granule cell inputs? 2) Are Purlinje cells more responsive to gr_.anule cells just underneath them compared-with more distal ones arriving through parallel fibers (PFs)? To address these cluestions, we recoi'ded in vivo Pfirkinje cell activity extracellularly, concurrently with voltage-sensitive dye (VSD) imaging of the surrounding cerebellar cortex. The signal was acquired from new blue VSDs at high rates (2.8--5.5 kHz) usmg a 464-photodiode array (amphtudes of 0.1-0.8% dF/F). To address the first question we.compared responses of direct. PF stimulation to responses obtained by p.eripheral stimulation. We found that while direct activation of PFs elicited a "beam" of activity propagating along the parallel-fiber axis, .peripheral stimulation resulted in a simultaneous activation of an irregu_lar patch-like area, exhibiting no spread along the PF axis. This suggests that Purkinje cell.s are more sensiti_ve to the anule cells just underneath them, as a signincant contribution from PFs would result in a beam-like response. To study the second question, we performed spike-triggered averaging of the optical signal on spontaneous Pur..kinj. ce!l simple spikes. Simple spike activity was not correlated with any structured activity n the .urrounding cerebellar cortex.
This supports the idea_ that simple spikes arise spontaneously as a result of intrinsic neuronal properties, and not due to random granule cell inputs. Functional magnetic resonance imaging (fMRI) of primary olfactory cortex (POC) has yielded inconsistent results. Odorant-induced POC activity is present at times and absent at others even within the same lab using the same task. Most statistical models used to analyze fMRI data rely on two assumptions: 1. a monotonic transform from stimulus magnitude to neural activity quantity, and 2. a linear transform from neural activity, quantity to MR signal maenitude. Whereas the latter has been demonstrated-for Mff' (Boynton et al 1996), the former has not been 29 demonstrated for POC. An equally viable alternative to a rate-encoding model is a temporal-encoding model. Models of temporal-encoding do not necessarily imply a monotonic transfdrm from stiinulus magnitude to neural activity_ quaptity. Thus, fMR1 is a potentially invalid measure of P.OC activity under temporal-encoding models. To address this issue we set out to quantify the stimulus magnitude dependence in POC in thirty_ subjects. An olfactometer generated low, medium and high concentrations of .the &torantsphenethyl alcohol andpropionie acid in an eventrelated design (4T, T2* GEMS, TE=28ms, TR=lsee, 192ram FOV, 8 slices, 0.5ram skip, 3x3x3.5mm voxel, ISI=30sec, stimulus repetition=27). The initial 6 subjects of prppioni acid had significant activation overall in lateral orbital fronal cortex (p<.05) and in POC (F(3 20)=3.44, p<.03). The relationship between increased sgnal and increased stimulus concentration in POC was monotonic but not linear (approximately logarithmic). We will test if this finding is the nature of POC encoding or is the consequence of another factor. For example, m several 9f these initial subjects the signal in POC appeared to be confounded by individual sniff d.ynamics. Final data analysis will include regressors based on individual sniffs to reduce this variability.

Follow-up on White Matter Changes in Stroke
Ki M?, Bova I.2, Bornstein N?, Hendler T.', Assaf Y.' The L-E-G Institutef_or Functional Brain Imaging, Tel Aviv Medical Center and Tel Aviv University 2Deft. bf Neurology, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel; Diffusion MR/ is a common diagnosis tool for stroke despite the fact that diffusion changes following acute stroke are not fully understood. In addition, Diffusion Tensor Imaging (DTI), which is more sensitive to white matter, reveals mixed effects of fractional diffusion anisotropy (F.A.) ehges within the same subject in the acute stage without distinction of neuronal degeneration or tissue dislnt.egration. Thepurpose of the present s_tudy was to estimate the outcome of aras having increased FA at the acut.e stage of the strpke. For that we cSnducted a follow-.up study on seven stroke patients using diffusion MRI. Thi examinations were performed at two different time intervals following the stroke (less than 48 hours and more than 3 months). For data analysis, we segmented .the infarcted area into 5 regions of iriterested (ROIs) based on their FA values and followed their condition at the chronic phase using image co-registration. The results revealed two. different patterns of changes. One pattern was ehara.cterized by reducaon of both theTA and ADC values at the acute phase as compared to normal controls. In the chronic stage, the FA values decreased further reflecting white matter disintegration. Severe deterioration was observed at the ROIs that correlate with the core of the lesion, while slight reduction was observed at the ROIs that correlate with the penumbra of the lesion. In the second pattern, at the acu.t.e stage, the ADC reduction, at the ROIs that correlate with the core of the lesion, was accompanied with increased FA (as compared to control values). At the chronic stage the FA values approached control values. These two different patterns of cfianges may reflect different mechanisms of pathology. This preliminary, study suggests that higher FA valu.es, at tl!.e acute phase following schemic stroke, may pre.dict good tissue recovery., while reduction in FA values at the acute stage may predict further deterioration at the chronic phase.
The balance between production and continuous delamination of neural crest progenitors. Kalcheim C.., Krispin S.

Dept. of Anatomy and Cell Biology-Hebrew University-
Hadassah Medical School-Jerusalem 91120.; We have previously found that delamination of premigratory neural crest (NC)cells from the dorsal neural tube lepends both upon BMP/noggin signaling and successffil transition frtm GI to the S-phase of tlie cell cycle. These two mechanisms are hierarchiclly related as BMP is upstream of Wntl, which in turn promotes G1/S transition and NC delamination. In light of the continuous departure of NC cells from the tube upon syn.chronization to the S phase, we investigated the mechanism by which the premigratory pool of NC ceils is replenished. Two alter,ative models were ..l yzed. First, a stem cell model implying asymmetric cell divtsions in the dorsal midline, as a consequence of which, one dau.ghter cell delamina.tes while th8 other remains in the tube to generate another round of a delaminating cell+a stem cell. The second model involves the existence bf a dorsolateral source of NC cells, which translocate dorsomedially into the I)MP/Wnt domain and then delaminate (Source and sink model). Our data supp.ort the secxmd view of NC cell replenishment. These results are highly significant for our understanding of NC ontogen,y as well as of the histogenesis of the CNS primoramm Extracellular Regulated Kinase I/iI (ERKI/II) as a coincident detector of neuromodulaton and fast neurotransmission KaDhzan H., Rosenblum K.
De-ptl of Nerobiology and Ethology, Center for Brain and Behavior, University of Hafa; In order for a particular neural representation to become consolidated fo: longer periods, long lasting changes in the neural connectivity-should take pla_ce, as well as other intrinsic neural changes. These changes depend, upon molecular pro.eesses such as signal transdu.eton, transcription and protein synthesis. We hypothesize that in order for an afferent ionoopie "fast'-e_xperience (N-Methyl-D-Aspartate, NMDA) to be consolidated as a long term memory, it should come in convergence with another metabotropic "slow' modulatory. put-(Dopamine). First, we set up to define time anl dose curves of ERKII activation by D0pamine and NMDA in hippoeampal slice p_reparation. We fred that application bt' 10-I00 uM Dopamine creates a dose ddpendent rise in ERKII acttvation. When Dopamine is applied in 100uM it raises the ERKII activation m about 50%of basal level, in a time frame maximal at 5 minutes. We also fred that when NMDA is applied in different doses ranging from 10uM to 100uM it creates a dose dependent rise ifi ERKII activation. 100uM NMDA raises the ERKII activation in about 50% in a time frame maximal at 5 minutes. The kinetics of ERKII activation by 10uM and 100uM NMDA is different. Mutual application bf NMDA and Dopamine in the same temporal phase does not cause, any augmentation in ERKII activation. The results do not dishfiss the hypothesis of convergence in different temporal phases.  A basic problem in psychophysics is the independent esti..ate of the mean internal response and the noise amplitudes evoked by the sensory sttmulus. An an_alysis of the two-alternative force-choice method derived from the standard d.etection theory, frequently applied in studies of contrast discrimination, shows that this method is not suitable for the estimation of these unknown parameters (mean and variance). To overcome this problem we us.ed the Thurstonian scaling method of successive intervals.
Three observers were tested on a visual identification task, using Gabor signals at five contrast levels as targets. In each trial one of five targets was presented to the observer and he was asked to report _which one he saw, pressing the numeric keyboard button ttom one to five. The model parameters, namely, mean internal responses (n=5),. noise _amplitudes (n=5) and category boundaries (4 criteria) were found using a best least square fit to the data. In all experiments the noise amplitudes were found to be independent on the contrast. The internal responses were found to be best described by a saturating function of contrast. Surprisingly, the obtained criteria were uniformly distributed and not optimally, set. The confidence intervals for the model parameters obtained from the experiments were estimated using Monte-Carlo simulations of the identification task. The results show that the known increase of contrast discrimination thresholds with contrast is due to reduced sensory gain and not due to increasing internal noise.
Dept. of Phsio!ogy and Pharmacology, Sackler School of M,dicine, Tel-Aviv Uni-versity, Israel Kv2.1 has been shown to interact physically and functionally with t-SNAREs, Syg__tasin_ 1A and SNAP-25 (Michaelevski, 2003). Also, Kv2.2, exhibiting high sequence identity with Kv2.1 throughout the N-terminus and the core transmembrane region, but has a pro-found sequence divergence at their C-termini, interacts with Syntaxin IA and SNAP-25 (inpreparation). However, the interactions of both channels difftr (in preparation). Recently, we have shown that the Kv2.1 iriteracts also with VAMP-2. The central conserved domain of VAMP-2 has binding sites for both syntaxin 1A and SNAP-25 and is req.ui(_ed for SNARE complex formation and synapt.ic vesicle membrane fusion. In this study we characterize the interactions of Kv2.2 with VAMP-2 and compared with those of Kv2.1. A co-immunoprecipitation analysis, using antibody against Kv2.2 and Kv2.1 reveals physical _m.teractons of both channel proteins' with VANIP-2 in Xenopus oocYtes injected with the corresponding mRNAs. The functional implications of these physical interac-tions are revealed, using two-electrode voltage clamp analysis performed m Xenopus oo-cvtes. Thus, VAMP affects m a concentration depehdent mhnner both steady-state activation and inactivation of Kv2.1, i.e., shifting half-activation and half-inactivation poten-tials to more negative voltages without affecting the slope factor of both activation and inactivation. The same effects can be detected in Kv2.2, however, at lower VAMP,2 con-centrations, Namely, Kv2.2 is more sensitive to VAMP-2. Additionally, VAMP co-expression with ether Kv2.1 or Kv2.2 decreases the channel conductance in a dose-dependent manner. The effects of VAMP-2 were further iiavestigated in Kv2.2. Different temporal relationship between be injection of VAMP-2 and channel mRNAs were de-tected for the different effects of VAMP-2 on Kv2.2, indicating that the. reduced ampli-tudes are probably, due to impaired trafficking to plasma membrane and/tr synthesis. Dept. OfNeurobiology,_ Weizmann Inst. Of Science, Rehovot, 76100, Israel" Receptive fields of neurons in the barrel cortex are composed of several whiskers. Thalamic receptive fields however are not limited to a single whisker. Thus it is not clear if multi-whisker receptive field of cortical neurons is determined by convergence at the cortical level or by their thalamic affe-rents. To examine at what stage conver;ence occurs and to estimate the portion of common inputs arriving to a cortical neuron we used the known _adapting behavior of cortical cells as a tool. Adaptation or cortical neurons is believed to result from _d_epre.ssion of the thalamocortical and cortical synapses. Thdrefore reduction of response t.o stimulation of one Whisker after adapting the cell to stimulation of another whisker is a possible evidence for cortical cross talk or shared inputs. Indeed we show, us.ing several simultaneous e.xtracelluar recordings, tha.t adaptation to repetitive stimulation is strong m cortical neurons and almost absent in thalamic neurons. Average membrane potential recorded .from neurons of. different cortical layers. To calculate the percentage ot common inputs out of the total respon_.se of one of the whiskers we us/ed a simple linear model. We assumed that the response after depressing one pathway is an algebraic sum of the not a.dapted non shared in_puts and of sliared inputs_ that were ad@ted by the second pathway. On average -40% of the _mputs are shared, however, we found large variability in thi shared inputs across cell population.-Examination of various parameters reveals that th portion of shared inputs is relatdd to recording depth. Assumed layer IV .cells showed the smallest pbrfi_on of shared input while cells from other layers showed larger portions. Our results are in agreement wth anatomical arid e_leetrophysiolocal studies suggesting that convergence of spatay disiinet inputs There is indirect evidence that anti-P-ribosomal Abs is associated with CNS disease. Anti-P-ribosomal autoantibodies occur specifically in systemic lup erythematosus (SLE). These antibodies are detected predominantly in patients during the active phase of the disease and are believed to correlate with CNS involvement and nep!?.ritis. The aim of study was to examine the pathogenic role of anti-P-ribosomal in animal models by mtraeerebroventrieular (i.c.v.) injection of polyelonal ant-P-ribosomal affinity purified Abs from palae.nt.s with SLE.
Naive female mice (C3H/Hej) were injected i.c.v, with 6 mg/ml anti-P-ribosomal Abs or with 6 mg/ml IVIg as control. The mice were examined for neurological dysfunction in a staircase test, cognitive swim T-maze, grip strengtl.x, Rota rod, elevated plus maze (EPM), forced swmfming test fiST), and passive avoidance. Anti-Pribosomal Abs injected mice had a significantly different behavior in the EPM and FST compared to controls. In the EPM, the mice injected with ant-P-ribosomal Abs had significantly less exploration and were less active compared to the controls, hi the FST, the anti-P-ribosomal Abs injected mice were found si_gni.ficantly more depressed (a significantly prolonged immobility time) compared to the controls. No significant differences were found-between the study and the control groups in the staircase, grip strength, Rota rod, and cognti've (swim T-maze and passive avoidance) tests. Conclusions: Anti-P-ribosomal injected mice display highly significant behavioral changes compatible with depression. No motor or cogrfi_tive effects were found in this model. This unique model may be relevant to the pathogenesis of depression in SLE patients.
Effects of controllable vs. uncontrollable stress on amygdalar neuronal activity and plasticity.
Kavushansl A.., Richter-Levin G. Brain and Behavior Center, University of Haijkt; We studied the effects of controllable versus uncontrollable stress on neuronal activity and synaptic plasticity in the .amygdala, using the electrophysiolocal procedure of long-term potentiation (LTP) induction. Rats of the controllable stress group were presented with I00 trials of a tone followed by-a toot shock in a two-way shuttle avoidance box. The controllable stress group could avoid the shock by pressing a bar during the tone, or escape the shock by passing to the opposite side of the box during the shock. From tliis group two sub-gr0ups emerged: rats which learned the task well and avoided more than 50 shocks (good learners) and those which avoided less than 50 shocks (bad learners). Rats of the uncontrollable stress group could not avoid or escape the shocks which were presented according to the averageperformance of the good learners. A naive group was left undisturbed until-the recording commenced. Immediately after the training rats were anesthetized and prepared for stimulating the entorhinal cortex and recording in the a._rgygdala. The neuronal activity was not significantly affected bv the traimng. The good learners did not differ from the nves, but the bad learners and uncontrollable stress groups showed less LTP than the naives and the good learners. There was no difference in LTP between the bad learners and the uncontrollable stress group. These results show that a strong s.tressor reduce.s amy [gdalar, synaptic, plastici.ty, and suggest that failure to learn the task might be emotionally perceived as uncontrollable situation.
Neuronal activity and plasticity in the amygdala, the dentate gyrus and the CA1, following controllable vs. uncontrrllable stress.
Kavushansky A._, Vouimba R., Richter-Levin G. Brain and Behavior Center, University ofHaifa; The level of controllabili has been shown to modulate effects of stress on physiology and behavior. We studied the effects of controlldble versus uncontrollable stress on neuronal activity and syn_aptic plasticity in the amygdala, t.he dentate gyr.us (DG) and the hippocampal CA 1, using the electrophyslological .procedur_e of long-term potentiation (LTP) induction in the rat. Rats of the controllable stress group were trained in the Morris water maze to locate a hidden underwater platform, thus escaping the cold water, immediately before the recording. The uncontrollable stress group was exposed to the water for the averaged time of the controllable group, without the platform. A fiaive group was left undisturbed until the recording commenced. The controllable stress group showed no difference from the naives in any of the measures in the dentate gyrus and in the amygdala. The uncontrollable stress increased baseline activity m the amygdala, and enhanced LTP in the dentate a-us. In the CA1, both stressors impaired LTP, but the effect of the uncontrollable stress was more robust. These fmdings were further verified in a second experiment in which the effects of anaygdalar activation on DG and CA1 activity and plasticity were assessed. Stimulation of the amygdala increased neuronal activity in DG, but not in _the CA1. Furthermore. amygdalar activation 30 s prior or after LTP induction increased LTP in DG, but decreased it in CA1. These findings show differential effects of stress, controllability and amygdalar activation on different brain regions, and suggest that the amygdala mediates some of the effects of stress on hippocampal-activity and plasticity.
Constraining compartmental models using multiple voltage-recordings and evolutionary algorithms Keren N.., Korngreen A. Faculty ofLle Sciences, Bar-Ilan University; In the last decade there has been a significant advancement in the ability to record membrane potential and ion channels from dendrites. Compartmental models with many non-linearly dependent parameters are used to learn the physiolog3 of such complex neurons. However, the number of loosel-3 constrained parameters makes it impossible to constnct the desired model manually. Recently, progress has been made using automated parameter search methods, such as evolutionary algorithms. These stochastic algorithms enable to construct a compartmental model of a neuron, using recorded spike trains. However, these methods are limited to somatically recorded spikes using relatively simple target functions. We've used a new fitting method based on trajectory density in a phase plane to compute a robust fitness coefficient. We exclude the time parameter by plotting the membrane potential V(t),versus ts first time-derivative V'(t), in which the periodicit of the signal is reflected by a closed loop that can be geometrically analyzed, and each point bf the plane can count how m.any times it has been hit during the entire recording. This method prevents from the algorithm to ignore the steep spikes and us cony _e[ge into a strait line.
We investigated the contribution of several recording locations (soma, dendrites and axon). At each location a set of 5 currents (2 passive + 3 spike trains) was measured. We combined least square sum ftinction for the passive currents with the trajectory density for the spiked ones. We concluded that convergence efficiency improves as more recording locations are used.
Proteolytic processing of F-spondin is required to elicit its affect on commissural axon fasciculat[on at the toor plate Khazanov S.', Marom K., Klar A. h-tomy and Cell Biology_, Hebrew University Hadassah Medical School Jerusalem, Israel; F-spondin, a gene expresse.d at e floor plate, encodes a secreted guidance protein that plays a role in patterning axonal trajectory in the spinal coi'd. The cboxyt half of Fspondin, Which" contains 6 thrombospondin type repeats (TSR), isproteolsically processed. The cleaved products of F-spondin have diffei'ent properties and activities: the 1-4 TS.R fragment neither 15nd-s the ECM nor promotes axonal outgrowth, while the 5th and 6th TSRs bind ECM and promote outgrowth. To test the relevance of F-spondin processing in-vivo, we applied genetic tools to the chick embryo. Cell-specific expresson was achieved _by electroporation bf DNA utilizing a floor plate specific enhancer. The activity of the specific enhancer was further amplified by the use of DNA site-specific Cre recombinase andPlox conditional constructs. The ectopicallv expressed 1-4 TSR domain is deposited along the membrkne of floor plate cells while the 6th TSR is found in the basement membrane' underlying the floor plate, reflecting its ECM binding propertie. 13y utilizing protein tags at the amino and carboxyl ends of the protein, we demonstrate that Fspondin is processed in vivo. Mutating the putative cleava[ge sites generated a non-cleavable protein, comprising the two domains, that accumulat.ed on the surffice offloor plate cells. The re-routing of the neurite outgrowth-promoting domain of F-spondin to the membrane of the tloorplate cells, rather than to the basement membrane, resulted in re-directing commissural axons growth dorsally into the floor plate cells. Thus the cleavage of F-spondin is required for the depps..ition of the adhesive motifs at the basement membrane, which can then facilitate the fasciculation of commissural axons at the ECM below the floor plate. Ben Gurion University, Beer Sheva; Autoimmune T cells have been shown to benefit neuronal survival after CNS injury, and hence to help maintain the equilibrium of motor and sensory functions of the brain under adverse conditions. In this study we found that T cells play a role in spatial learning and inemory both under physiological and adverse conditions, e.8. neurodegeneration or dementia. We found that in mice with severe lmmtme deficiency long-term potentiation (LTP) and learning and memory "processes are mpaired and adult neurogenesis is significaht!y reduced. Replenishraent of the immune deficient mice with T cells restored hippocampal plasticity. Under adverse conditions, caused -by neurotransmitter imbalance, a T cell-based vaccination was 32 sufficient to overcome the behavioral malfunctioning. The beneficial effect is attributed in part to brain-derived neurotrophic factor (BDNF). These findings, by suggesting that a peripheral immune deficit or a local neurotransmitter imbalance or both can lead to cognitive impairment, highlight the role of the peripheral immune system in CNS mintenance.
Dept. of Neurobiology, Weizmann lnsitute of Science, Rehovot, Israel; The relative simplicity of the rodent vibrissal system facilitates a systemattc study of motor control and sensorimotor loop dynamics. Multiple anatomical loops con.tribute to actwe control of the vibrissal plant during explorative behavior. We have examined motor control d_ui'ing .exploratory and task-related Whisking in rats and mice. Using high-speed video we monitored whisker trajectories and extracted various kinematic parameters from the whisker motion. We analyzed repetitive whisker movements with a forward (protraction) and a backward (retraction) phase. We found that, across tasks, the ptraction phase during high-amplitude whisks .is characterized by a pulsatile forwkrd motion with relatively constant velocity. The amplitude of protraction is governed primarily by the duration of movement whereas retraction amplitude scales primarily with veloci. During protraction, obiect touch is followed by a rapid (~10 ms) active thrust of the ongoing movement:, typically observed as an increase in whisker velocity. These observations are consistent with the notion that thd protraction phase acts as the sensory acquisition stage during whisking and that rapid brain loops can process arid adjust pre-planned movement trajectories in the behaving rodent. There is mounting evidence to support the concept of education producing a functional reserve in the briin, a process that provides some protection against the clinical manifestation of severe CNS illness. At the molecular level BDNF was suggested to mediate memory consolidation and synaptic plasticity produced by leamirig experience. This study aimed to examine whether pre-challenge learning prevents psychosis-like behavior iri an animal model o-f schizophrenm, and to describe the learning-related cellular mechanisms which attenuate the course of sehiz0penia. Rats were trained to distinguish between pairs of &lors in an olfactory discrimination task. We examined whether such olfactory-learning induces protection against the effects or i.p. injections of MK801 m a series ofbehavioral tasks, the Morris water-maze, pre-pulse inhibition and elevated plus maze. Forty-eight liours after the behavioral tasks, rats were sacrificed and the frontal cortex, CA1, CA3 and dentate gyrus were dissected for BDNF measurements.
MK801 caus sensory-motor disturbances, spatial learning acquisition deficit, and swimming strategy alterations in pseudo trained and naive rats, to the point were they were unable to complete the task during the course of 4 day_s of training. Although MK801 strongly affected learning oF rats from the olfactory-discrimination trained group, these rats performed better than the naive and pseudo trained, and were able to complete the task. Moreover, administration .of MK-801 significantly disrupted pre-pulse ir. ibition i.n the pseudo-trained and naive grg_ups, but not in the trained rats.
In learning rats, BDNF riaRNA in the frontal cortex was significantly higher comp .ared to naive and pseudo-learning rats. Our data support the notion that learning-induced protection against schizophrenic behavior is mediated by' glutamatergic transmission and modifications in the fromal cortex, manifested as enhanced expression of BDNF mRNA levels. Currents yielded from voltage-clamp recordings performed in non-isopotential structure.s, such as dendrites,..are severely distorted due to voltage attenuation around the injecting electrode. Therefore, up till now it has been impossible to determine correctly the underlying ionic conductances of voltage-gated channels distributed in the membranes of such structures, and from them to accurately estimate channel densities. Recently, a numerical algorithm was developed by our lab, that has been shown to successfully correct such distortions in a number of simulated experiments using various neuronal structures inserted with a number of models of voltage gated potassium channels, and correctly estimate channel kilieties hnd conductance densities when inserting a range of homogenous densities and even density gr.adients and slopes. However, one hmitation of this correction algorithm is relatively poor spatial resolution, when estamat.ing conductances in structures inserted with a step-wise vary_'_m.
channel density, around the abrupt conductance step..This study shows an improvement in spatial resolution adhieved by performing a sequence of voltage clamp simulations in locations progressively closer to the position of the conductance step each time utilizing the conductances estimated in the farther positions. These improvements ".m kinetics and density estimations were successful with various potassium channel models and a series of increasingly larger eonductarlee density steps,. spines. Axons were labeled by the anterograde transport of lysine-fixable biotinylated dextran amine (BDA) injected in vivo into the ventrobasal thalamus. Labeled thalamic axons in the posteromedial barrel subfield were identified by light microscopy, serial thin sectioned and then reconstructed-in 3-D from digital electron micrographs. All thalamocortical synapses were of the asymmetrical type. Most were formed at varicosities, however, some occurred at cylindrical regions of the afferents. Preliminary results indicate that axonal varicosities form about two synapses each, a lower value than observed in preparations where lesion induced degeneration (LID) has been used to label thalamic afferents. It may be that during degeneration, the axonal varicosities coalescence and/or 'absorb' synapses situated in adjacent non-varicose axonal se_grnents. The ratio of axospinous'to axodendritic synapses i_s 4:1; this ratio _has been observed for BDA labeled afferents at 11 days postnatal, and for LID and PHA-L labeled afferents in adults (White, 1989 Acute ALCAR (100 mg/kg), on the other hand (tested 6 hours after administrittion), demonstrated anxiogenic effects. Our data suggest that chronic ALCAR administration may. produce an inverted U-shape curve of dose dependent changes in anxie-like beliavior. The precise mechanism by which Acetyl-L-eamitine decreases anxiety-like behavior after peripheral administration remains to be determined.
Correlation between blood-free testosterone concentration and sleep duration in healthy young men Leviner U. , Gat Y., Gomish M? Background: Heal_thy young men who underwent varicocelle chemical embolisatlon, required reduced sleep duration. Testosterone, an androgemc anabolic steroid, affects the central nervous system. We measured serum free testosterone in a group of these patients, to determine whether there is a correlation with decrease sleep duration. Methods: Th_trty young men in general good health, underwent varicoeelle chemical embolisation for infertility treatment. They were requested to complete a questionna'.u'e regarding theil: sleep habits. They were asked to fill in the questionnaire before treatment and again 3 months after start of treatment. Serum free testosterone was measured at the same times. Results: In 40 young men (mean age 31 + 7) serum free testosterone increas&l 3 months alter the varicocelle procedure_(6.5 + 3.5 vs. 11 + 3.1; P < 0.05).

35
Coupling TMS with EEG to "dose the loop" between measurement and perturbation first steps towards a "brain pacemaker" yit Binn N, , Peled A., Moses E. Several antidepressants, mainly selective serotonm reuptake inhibitors (SSRIs) and tricyelic antidepressants (TCA.s), were shown to induce severe weight gain and metabohc changes, but the mechanism and thajor early key players underlying it remain unclear. In previous study we demonstrate marked dose-dependent activation of the c-Jtm amino-terminal kinases 0NK) patheway, following exposure to selective antidepressants. Also, JNK activation and p.hosphorylation has been shown to play a central role in olgesity and insulin resistance. Because selective antidepressant both induce severe weight gain and are potent JNK activation, the present study asked to characterize the molecular pathway underlying antidepressant-induced metabolic changes. First," we demonstrate that applying the antidepressant Paroxetin two .h_ours prior to insulin nduce insulin receptor activation, .signiticantly block insulin reeep_tor phospo.rylation in rat laepatoma cell (FAt). This effect was dose-dependent striding at dose of 1-10 ]YM Paroxetin. Paroxetin blockade of instilin receptor phosporylation did not accompaniment with changes in the levelof insulin receptor protein. These changes ifi insulin receptor activation were correlated with rapid-increases in p-c-Jim levels and the upstream target, p-JNK. To check for non-specific activation of other MAPK pathways, e.g. the MEKJERK pathway, we determined p-Erk aeuvation under the same conditions and found that c-Jinx, but not p-Erk, was activated by paroxetine. To test if paroxetin induced insulin receptor phbs_Eorylation depend on c-Jun activation, we used the specific e-Jtm activity blocker, SP 600126. We found that paroxetin effect on insulin rec_eptor activation abolish if we block c-Jun activ.ation. In this study we suggest a central role for JNK in antidepressant-inducedobesity and metabolic changes. The development of drug addiction is associated with synaptic plasticity and neuronal adaptations including alterhtions in glutamate reeept0rs such as GIuR1 and NMDAR1 in reward-related brain regions, mainly in the mesoaceumbens pathway. Intra-cranial self-stim.ulation of the medial forebiain bundle (MFB) was reported to affect glutamatergie transmission and reeeptgr levels in these. egio .ns. We i_nv.esti.ga_te_d the .influence of.repeated eleegi .cal sttmulation of the MFB on the sensitized response and the seeking behavior for eoc.zfine in rats preyious-ly exposed to daily cocaine. In addition, we examined t-he level of glutamate receptor subtypes (NMDAR1 and GluR1) in the mesoace.u, mben.s path'ay of these rats using immunonhistoehemstry. Chronic cocaine injections (15m.g/Kg/day for 7 days) induced a gradual inerea in the psychomotor respon.e: as previously r_eport_ed. Chronic treatment with electrica! stimulation ot" the MFB (ten days, 30 min/day) did not affect the sensitized psychomotor response to a cocaine challenge. However, in a following saline challenge, which typically induces conditioned pehomotor ativation, the-chronically stirrmlaled rats did not show psychomotor activation. Furthermore, the electrical stirhulation treatment induced some alterations in NMDAR1 levels in the mesoaccumbens..., pathway. Other groups of rats were trained to set-aaminister cocaine in an operant chamber. We found that the electrical stimulation treatment caused a decrease in cocaine seeking behavior in a. drug-.free tri.al. These results indicate that repea.tgd electrical stimulation of the MFB fails to attenuate the psychomotor and perhaps the rewarding effects of cocaine per se but it does attenuate the incentive effects of the drug-. related cues. The attenuation induced by the electrical stimulation may result from changing synaptie stren.g.th that is related to th incentive salience of drug:associated cues. Hence, we suggest a potential treatment f-or addiction using electrical stimulation. responses when neighboring whiskers are coactivated was reveled by blockade of inhibition using bicucullin (Kiazi et at. 1996). However, the exact mechanism that leads to sublinear spatial integration remains unclear. Here we explored the mechanism of spatial inteation by_ recording the membrane potential of neurons in the barrel cortex 6f the rat. We studied the integration of excitatory and inhibitory components arriving to the cell from two sensory pathways by stimulating tw 9 neigh_boring whiskers. Conductance measurements and intraeellular-bloekade of inhibition demonstrated directly that excitatory components arriving from the pathways are summed almost l'mearly, suggesting that excitatory inputs do not share significant amount of common inputs and are independent from one another. On the other hand, inhibitory components are summed supralinearly: inhibition was on .average-50% larger than predicted. These findings strongly suggest that sul5 linear spatial integration /u'ises fi'6m nonlinear properties of the cortical network leading to activation of intubitory inputs that are not activated by either stimulus alone. Ability. to cope with ongoing neurodegeneration after optic nerve injury differs among hnimal strains and depends on the ability to manifest a T cell-mediated protective response. In strains that show a higher neuronal survival following inj_uy this ability also correlates with wellcontrolled, moderate, transient activation of local microglia to express MHC-II. We show that CD4+ T cells fhat infiltrated mechanically injured nerves in mice that varyin their ability to cope with the _injury exhibited similar memory phenotypes, after 3 days the percentage of activated CD4'--T cells was significantly higher in mice with the higher neuronal survival. Both stratus benefited from active immunization with myelin-related antigens.
However, immune-based manipulations (via mucosal administration) evoking regulatory-cell g0nerati.on and a shift in cytokine balance were neuroprotective only in mice with poor ability to cope with the insult and only when .directed against certain epitopes. The results support a link between poor ability to cope with injury and susceptibility to development of experimental autommune encephalomyelitis, and suggest that immune regulation as neuroprotective therapy sh6uld be considered with caution.

The B. Rappoaprt Faculty of Medicine Technion-lsrael Institute Of TeChnology Haifa 31096;
Parkinson's disease (PD) is one of the most common neurodegenerative diseases and it is due to a progressive de,generation of dopammergic neurons in substantia nigra.
Mutations in the aIpha-synuclein, gene and its presence in Lewy bodies of PD patients indicate that alpha-synuclein play an important role in the disease. We have found that alpha-synuclin interacts with a protein we have called synphihn-1. Synphilin-1 is enriched in brain, interacts with alpha-synucletn n vivo and is present in Lewy bodies of PD patients. Co-transfection of synphilin-1 with alphasynuclein into mammalian cells leads to the formation of eosinophilic inclusions that resemble Le.wy bodies, suggesting that synphilin-1 could modulate alpha-synuclein aggregation. We also found that synphilin-1 is a neuronal proteih, widely expressed in brain and localized to presynaptic nerve terminals. Co-immunoprecipitation experiments show that synphilin-1 specifically associates with synaptic vesicles. More recently we found that synphihn-1interacts with the ubiquitin-hgase called SIAH. SIAH promotes the ubiquitylatmn and degradation of synphihn-1 through the ulAiquitin-proteasome system, and the formation of robust amount ofinclusion b6dies in the presence of 9rpteasome inhibitors...<Ubiquitylation is required for nclusion formation, since a catalytically inactive mutant of SIAH, which still binds to synplin-1, fails to promote inclusions. SIAH is pr._es._.nt in.. Lewy bodies of patients with PD, raising the possibility that snplin-1/SIAH inclusions may "be relevant for Lewy body formation. We _hypothesize that dysfunction of ubiq.uitin-. proteasome pathway and accumulation of ubiquitylated s_Lnphilin-1 could b.e an early event in the pathogenesis of PDI We are currently extending our studie.s on synphilin-1- We previously showed in neoeortical neurons that when all voltage-depefident channels are blocked, a large, nonspecific, outwardly rectifying, cationic current is revealed (Icat). The characteristics of/cat are rapidl_y altered duri0.g an hypoxic episode, which elicits a si-_cant increase in the !nward Icat. at negative voltages and a parallel decrease in the outward current at depolarized voltages. We now show that Icat is also activated by a drop in extracellular Ca2+ to nanomolar concentrations, such as may occur during hypersynchronous neural activity and seizure.
Reduction of [Ca2+]o resulted in complete loss of Ieat rectification, massive influx of cations at negative potentials and consequent membrane d.epolarization. Using cell-attached recordirigs from Ca2+-activated K+ channels, we monitored membrane potential and changes in [Ca2+]i. Hypoxia elicited a large, reversible depolai'ization which was accompanied by up to 1000-fold increase in [Ca2+]i. These changes in Icat properties during hypoxia or during activity associated with seizures may_ contribute to neuronal vulnerability by providing a route/or fion entrance and thereby depolarizmg the neurons and increasing [Ca2+]i. It is notew0_rflay that many of the properties of Icat, including its partial blockade by La3+, are similar to those previously reported for TRP channel-mediated.currents, whi/h are also very sensitive to metabolic stress. It thus seems likely that in neocortex, as elsew.here, cha..ges in thepropertles of TRP channels directly contribute to tile neuronal pathogenic responses.

Supported by a European Community Marie Cure
FeTlowship.
Animal models for investigating the basis ofthe Thyroid hormon T3"s activity in the treatment of depression Lifschvtz [., Shalom G., Lerer B., Gur E., Newman ME. Bioloqc Psychia__ Laboratory, Dept. of Psychiatry, Hadassah medical Center, Jerusalem.; T3 is long being used in the clinical setting for treating depressed patients, in two major paradigrns: 1) monotherapyin which T3 is given as a sole agent. 2) augmentation and acceleration-n which T3 is gifen as a supplementation to an antidepressant in order to induce a response to the drug or_to accelerate an existent response, to it, respectively. In order to investigate the basis to this clinical activity of T3, we first employed the in vivo microdialysis technique in order to measure the activity of presynaptic inhibitgry serotonergic receptors and serotonin levels n selected brain areas. We hypothesized that significant changes in these parameters valties may account for the clinical effects of T3. These changes (namely: the desensitization of the receptors, and the elevation of the serotonin levels) were found, in male rats, in a way that more indicates T3's value as a sole pharmacotherapeutical agent and less as an effective supplement to increase or to accelerate the activity of another antidepressant. In contrast, the measured parameters didn't change appreciably in female rats, either in the model mimicking T3 monotherapy or in the augmentation model. In order to create a lihk between the pharmacodynamical changes we've measured and the known activity of T3 in the chnical setting, and in 37 order to further elucidate the gender differences found in the microdialysis experiments, we've employed the behavioral parhdigrn of the modified forced swim test to rats of both genders. No consistent effect was found in this test to T3 and fluoxetine given in low doses for 2 weeks, bm high T3 doses given for a week did generate an antidepressant effect, but only in female rats and only in a delayed fashion (72 hours fter the last injection), again constituting a marked gender difference.
Distribution of the pro-apoptotic protein ARTS in rat The distribution of the pro-apoptotic protein ARTS (Apoptosis Related protein in the TGF-beta Signalling path,hay) has been examined by immuno-histochemica] technique in normal rat (Sprag._e-Dawley) formalin-fixed brain. The antibody employed (K21) was directed against the unique C-terminal 27 amino acids of the human ARTS molecule. This antibody gave a single dominant band in rat brain tissue (cortex, sti'iatum and cerebellum) by Western blot at apparent molecular weight of about 27 Kd, similar to that of htiman ARTS. ARTS was constitutively expressed in a proportion of neurons in most parts of the brain. In cortex many. ARTS-laositive cells were seen in the external and internfil pyramidal cell layers. The piriform cortex showed a high density of stairied cells. In hippocampus, most ne_urons in the pamidal cell layer were ARTSpositive. In striatum, medium spiny neurons were generally not ARTS-positive, but a small number of interneurons showed dense ARTS staining. In the substantia nigra, neurons of both pars compaeta and pars reticulata showed ARTS-positive staining in cytoplasmic and nuclear mponents. Double fluorescent staining was performed to detect co-localisation of ARTS and ty(.osine hydroxylase in the pars compacta. Most ARTS-posmve neurons were not tyrosine hydfoxylase-positive, but a small percentage of neurons were positive for both ARTS and tyrosine hydroxylase. In many, but not all neurons, ARTS occurs in nuclei as well as in the cytoplasmatic compartment. This contrasts with the picture seen following ARTS overexpression in peripheral cell lines such as Cos, Hela, in which ARTS has a predominantly mitochondrial occurrence, and enters nucle at the onset of apoptosis. The significance of this finding is not currently clear. Supported by a grant from the Chutack Fund Technion. largely ARTS-immunonegative. In ms, ARTS-positive cells were seen in periaqueductal gray, pontine mucleus, red nucleus and substantia nigra. In the latter areas, the intensity of staining was mkedly increased in PD brains. ARTS expression level was quantatated by Western blotting from deep-frozen tissue. Siinilar levels were seen in cx (inferior temporal gyms)of normal, PD and AD brain, and in st of normal arid AD brain. Brain ARTS has a lower apparent molecular weight (about 28 Kd) than peripheral ARTS. Although ARTS levels do not markedly change in PD or AD brain, individual neurons may c_xprcss-high levels during the brief period of time that the apoptotc process is active. su_eeess. Previous research found that the presence or a r-e.terenee tone aids in the performance of difficult dis.crimination taks. A simple dmcrin.nation task asks the s_ubjeet to make a simple judgement about a tone pa_ir, e.g.
it two tones are the same or different. A difficult task requires a more detailed judgement, like identifying which tone ".m a p_air is the higher tone. It has been founl (K. Ban.ai '04) that ff one tone is a fixed reference, i.e. it is always the lower tone, then the difficult task becomes easy. To further investigate the efficacy of the reference tone we divised a new task where the reference tone was always 1000 Hz, but sometimes it was higher and sometimes it was lower than the othff tone in the p.air. 23 teenage girls were tested in the six conditions fix&l reference, variable reference and no reference in the .simple and difficult paradigms. In .t]ae sirnplc paradigm the just noticiblc differences ON.D) for the vanhble reference condition were the same as in the fixed reference condition (-7% vs.-I0%). In the difficult para..digrn, on the other hand, JNDs in the variable reference conditaon were like those when no reference was present (-20.A). These results indicate that a reference s on! useful when it can be given a label in this case "low Possibly, t.his ability o categorize is what changes, a difficult task, using more memory resources, into a simpler less demanding task.
Expression of the pro-apoptoticprotein ARTS in normal human brain and in Alzheimer"s and Parkinson"s diseases. Loboda Y., Kemeny S.', Riederer P., Larisch S. and Finberg J.' 'Rqppaport Faculty qfMedicme, Technion, Haifa, Israel; U-nversity of Wurzturg, Germany; The pro-apoptotic protein ARTS (Apoptosis Related proteifi in the TGF-beta Signalling pathway) is a broadly. apopt.o.sis induction by several different pro-apoptotic stimuli is enhanced. The occurrence of ARTS in normal and Parkinsonian (PD) brain has been studied by immunohistochemistry, and in PD and Aleimer's disease (AD) brain by Western blotting using antibodies specific for the unique C-terminal 27 amino acids of the ARTS molecule. Expression of ARTS in individual neuronal cells was studied m paraffin blocks of tissue from cortex (cx), hippocampus (hp), cerebellum (cb) striatum (st) and mesencephalon (ms). In cx and' hp, light ARTSimmunopositive staining was seen in a small proportion of neurons, mainly the large py:amidal cells. Cb and st were DHEA and cocaine seeking behavior Maavan R.', Lotan S.', Kinor N. , Doron R.2, Yadid G.
iBoiogbai Psychiatry__ Lab., FMRC, campus Beilmson and Tel-Aviv univers#y;_ *Biological Psychiatry Lab, Bar-llan university, Ramat-Gan; The aim of this study was to determine weather neurosteroids are involved in cocaine addiction and abuse.
The effect of chronic DHEA injection on cocaine-seeking behavior was tested using the self-administration model. Ih addition rats were tested for brain neurosteroids levels following chronic exposure to cocaine. We also tested brain levels of different neurotransmitters (NT) known to be involved in the brain reward system, following chronic DHEA injection. Behavioral tests showed that DHEA attenuates cocaine-seeking behavior in rats. Biochemical tests revealed that DHEA elevates levels of relevant NT's weDA, 5-HT) in brain regions involved in the reward system. also found that lonic exposure to cocaine increases the levels of neurosteroids m different brain regions. Conclusions: neurosteroids are involved in mood, motivation and. reward. DHEA modulates the response to cocaine reward, acting as an anti-craving agent. Increased DHEA brain levels following cocaine self-administration support a.proteetive role for ttiis neurosteroid by helping to. Background/Aims: Hepatic encephalopathy (ttE) is a maior neuropsvchiatric complication of bofla acute and chrohic liver t'aflure. However the pathogenesis of th.is disease is still .unkn.own. It has' been suggested, that the cognitive deficits characterizing this state result from changes .in sgme neurotransmitter systems in the brain, including the Kl.utama.tergic, choliner.ic_and monoaminergic systems. lhese changes may result from an ammonia accumulation in the circulation and in the brain due to an impaired metabolism of this substance by the liver. Endocannabinoids ftmction as neurotransmitters and in the CNS via specific receptors. cently the endocannabingid system was found io be involved in the vasodilated state associated with liver cirrhosis. Aims: We h.ypothesize that the endocannabmoid sy.stem mizht be involeed also in Hepatic ence.phalol2athy.
. In primates, m.ultimod.al neurons representing peripersonal space, re.spond to tactile stimuli app]ied to the hand, and.to a visual stimulus when p,resenf i.n proximity to _the monkey's hand. This indiea.tes the existence ot a mechanism for inteating visual-tactile information, which is centered on bo.d.y p.arts. Analogously, recent neuropsychological studies with extinction patients, suggest a murtisensory representation of nearby space in humans.
Such a rel3resentation should lead to different p.atterns of activity when a visual stimulus is approaching.a body.part, than when it is far from the body. (although both stimul are prese.nt in the sarge position on the r.etma)..Using ..fMRI, we tested this hypotlaess: we presented visual stimuli moving towards .a target on the subject's hand ("near"),. and compared it wfih the case in which the same stimuli are novng towards a further targ.e.t ("far"). The contras.t etween the "near" and "far" conditions showed substantial activation in frontal and parietal areas (BA 6 and 40), which corresp.ond to regions representing peripersonal space in mofikeys. To account for. possilSle .differences stemm..ing me.rely due to the. different locations 91 the visual stimuli n the two conditions, we repeated the same procedure, only this time t.he subject's hand was positioned tar away from both stimulus tr.ajectories. However, und.er these conditions, no differential activation was seen in the referred areas. These results suggest that visual information m these areas is encoded in tile hand's coordinate flame. Future experiments will examine whether the hand position is visually determined, or rather based on proprioception.
Our results may shed more light, about the way nformation from different modalities (i.e. vision touch and pr_oprioception) are integrated to form th human body schema.
A dual role for cAMP in regulating myelin phagocytosis by microglia/macrophages Makranz C, 1'2, Cohen G.'.'., Reichert F.',', Rotshenker S. ',' l-d-gyl Hebrew University-Hadassah Medical School; "Eric Roland Center for Neurodegenerative Diseases, Jerusalem; Microglia/maerophages play critical roles m CNS and PNS injury and disease. One is the removal of degenerating myelin by phagocytosis. Myelin degeneration occurs after injury to axons and in autoimmune de_myelinating diseases such as multiple sclerosis and EAE. Degenerated myelin inhibits axonal regeneration and further activates the complement system to form membrane attack complexes that disintegrate intact myelin and axons. The rapid removal of degenerating myelin is vital, therefore, for repair and for minimizing damage to intact myelin and axons. In injury, myelin phagoczt_osis is mediated by complement-receptor-3 (CR3/MAC-1) and scavengerreceptor-AI/II (SRAI/II). We examined the role of cAMP in CR3/MAC-1 and SRAI/II mediated myelin phagocytosis. Elevation of cAMP levels by 8-bromo-cAMP (mimics cAMP), forskolin (activates adenylyl cyclase to produce cAMP) and IBMX (inhibits phosphodiesteras_.es that hydrolyze cAMP) inhibited myelin phagocytosis, r'ertussis toxin., Which elevates cAMP levels by ifihibiting Gi protein mediated inhibition of adeny!yl cyelase, further inhibited myelin phagoeytosis. Gi protein coupled recept.ors may thus up-regulate myelin phagocy[_osis by inhibiting adnylyl cyelase and consequently reducing cAMP levels, cAMPdependent protein kinase A (PKA) mediates most of the effects of cAMP. We thus expected PKA inhibition to augment phagocytosis. Surprisingly, PKA inhibition y Hg9 and PKA-inhibitor peptde, inhibited myelin phagocytosis, cAMP activated-PKA thus augmented myelin phagocytosis. A dual roleaugmentation and inhibition of CR3/MAC-1 and SRAI/II mediated myelin phagocytosisis thus suggested for cAMP. Such dual effect could take place by cAMP acti.ng in distract cellular compartments; via PICA and as yet unidentified another target molecule(s).
In-context trai_n!ng prior to stress exposure reduces the after-effects of the stressor: The role of brain derived neurotrophic factor (BDNF) Malka Y__, Kozlovsky N., Kaplan Z., Matar M., Cohen H. Ministry of Health Mental Health Center, Anxiety and Stress Research Unit, Ben-Gurion University.; Posttraumatic Stress Disorder (PTSD) does not develop in everyone exposed to a traumatic event. It is quite clear today that exposure to the stressor alone is not sufficient to trigger the disorders, and in fact a minority of those exposed will go on to develop the full-blown clinical conditions. Premorbid vulnerability and risk factors, are under extensive study, both at the behavioral and molecular levels. The aim of this study was threefold: to study the effect of m-context training prior to stress exposure on vulnerability and resilience in the development of acute and long-term behavioral changes in an animal model of posttraumatic stress disorder; to seek evidence for the involvement of these molecules; and to address the questi.on whether circulating levels of corticosterone influence the expression of the neurotrophic factors. Rats were randomly divided into 4 groups: 1) Trained rats in the Morris watermaze for 2 days (8 inputs /day) to locate the hidden platform (trained only). 2) Same as the first group plus an under-water trauma (30 seconds) the next dy (-trained + stress). 3). Nai've rats (Naive). 4). Naive animals that exposed to under water trauma (Naive + stress). One day after the trauma the rats were tested for behaviors associated with PTSD, including anxiety-like behavior as measured by the elevated plus-maze, hyperarousal as measured in the acoustic startle response, and spatial learning in the Morris water-maze. 24 hours later, the rats Were sacrificed and blood (for corticosterone) and brains area (for neurotrophic factors) were collected. Our preliminarv results have clearly shown that m-context spatial leaing prior to underwater stress reduced the aftereffects of the stressor and reduced the posttraumatic stress response in rats. Moreover, trained animals were less affected by the stressor than naive (but handled) animals.
The role of brain derived neurotrophic factor will be discussed. Recently, we found that juvenile rats trom two different depressed lines-the Flinders Sensitive Line (FSL) and their controls, Sprague-Dawl (SD) rats, and the Wistar Kyoto (WKY) hne and their controls, Wistar rats, show abnormality of the HPA axis. FSL juveniles demonstrated.
significantly lower plasma levels of corticosterone and ACTH, compared to their controls, while WKYjuveniles demonstrated siggificantly higher plasma levels 9 f corticosterone and ACTH compared to their controls.
.Experiment asked if these two different depressed lines have different basal levels in the hypothalamus of a neuropeptide which has behavioral eff6cts diametrically opposite to those of ACTH beta-endorphin. Experiment 2 examined HPA axis function of these two lines after chronic stress (-two weeks of social isolation). FSL juvenile rats demonstrated significantly higher basal levels Of betaendorphin and lower plasma levels of corticosterone ag.d ACTH after chronic stress, compared to their controls, while WKY juveniles demonstrat6d similar basal levels of beta-endorphm, and similar plasma levels of corticosterone but lower plasma levels of ACTH after chronic stress, compared to their controls. Both depressed lines showed sigmficantly lower levels of HPA h6rmones after chronic stress compared to basal levels, while the control lines showed stable unaltered levels of these hormones compared to basal levels. These results suggest that both FSL and WKY are genetic anim.a.l models of depression in adolescent rats, exhibiting distinct abnormal patterns of the HPA axis function at basl and reactive states.
Gene expression profiting of Parkinsonian substantia nigra pars compacta; Alterations in ubiquitinproteasome, cell adhesion/cellular matrix and related nes andel S.A. The Eve To_pfand USA NPF Centers, Technion-Rappaport Faculty ofMedicine Gene expression profiling of human substantia nigra pars compacta (SNpc) from Parkinson's disease (PD) patients, was examined employing high density microarrays. We identified alterations in the expression of 137 genes, with 68 down regulated and 69 up regulated. The down regulated genes belong to signal transduction, protein degradation (e.g. ubiquitin-proteasome subunits), dopaminergic transmissiori/metabolism, ion transport, protein modification/phosphorylation and energy pathways/glycolysis functional classes. Up-regulated genes, clustered mainly in biological processes involving cell adhesion/cytoskeleton, extracellular matrix components, cell cycle, protein modificatiophosphorylation, protein metabolism, transcription and inflammation/stress (e.g. key iron and oxygen sensor EGLN 1). One major finding m the present study is the particular decreased expression of SKP1A, a member of the SCF (E3) ligase complex specifically in the substantia nigra (SN) of sporadic parkinsonian patients, which may lead to a wide mpairment in the function of an entire repertoire of proteins subjected to regulatory ubiquitinaton. These findings reveal novel players in the neurodegenerative scenario and provide potential targets for the development of novel drug compounds. 'Dept. Cln.1Biochem., Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, lsrael; '-The Institute of Hematology: The Chaim Sheba Medical Center, Tel-Hashomer, Israel; Activi'-dependent neur0protective protein (ADNP) was recentl9 cloned in our laboratory (J Neurochem 199972, 1283" JBiol Chem 2001. ADNP is a novel 'zinc _finge's and homeodomain like profile containing protein. In a previous study, mouse ADNP was shown to be expressed at E7.5 with gradual increases duri_g embryogenesis (Brain Res DevBrain Res 2003 144, 3). To assess the function of ADNP, knockout mice (KO) were e.stablished= Embryos lacking the ADNP protein were shown to die at E-9-E9.5, an embryonic stage at which a series of major developmental ev.ents takes place. ADNP KO embryos were impaired at the stage o.f neural tube closure and brain formhtion. The current study was set out to reinforce these previous findings while revealing the specific pathways thi'ougth which ADNP operates. A 14000-Affymefid gene array_ was used in order to compare gene expression patterns or ADN_P KO embryos to normal and heterozygous 1.ittermates. Data was ahalyzed using the Aff_ymetnx web tools and the novel expender and prima software (Elkon et al. Genome Res. 2003, 13, 773). The data an.alysis enabled the lartial deduction of a pr.esumed mechanism by which ADNP deficiency may cause le.thality as follows. The lack of ADNP expression resulted in a dramatic down-regulation of a number of essential genes such as neurogeninl and neuroDl as well.as genes that. are associated with neuronal development and activity, such as galanin. Using non denaturing_protein gel ele.c.tt:op.horesi.s we have now shown that ADNP may interact directly with the neurogeninl promoter. As neurogeninl has been intimately associated in neurogenesis pafhways (Geling et al., Development. 2004131 1993  Fetal low brain oxygenation is associated with increased risk of fetal brain damage. Loss of GABAergic neurons was de.monstrated, in particular following pennatal asphyxia and anoxia in rats. A prophylactic treatment is maternal loading with MgSO4 (Mg). We have previously shown that Mg partially prevented-the fetal damage induced by hypoxia. Here we examined components of the GABAergic system in brains of adult mice, alter prenatal hypoxia (PH-2h of 9%02 3% CO2 on El7) and the interaction of Mg pretreatment'(4h Mg 75mg/kg) with the hypoxic effect.
Using IHC we show that PH did not modif3/the immunoreactivity to glutamate-decarboxylase 65/67 (.GAD, expressed in inhibitory cell soma and synapses) m the primary motor cortex (M1) region. However, when combined with Mg an increase in GAD was observed in layers 2-3 of M1. In contrast, the number of Parvalbumin (PV) cells in layers 2-3 of M1 was decreased by PH (73% of control, P<0.01), this effect was prevented by treatment with Mg. In layers 5-6 of M1, PH had a stronger effect: reduced number of PV cells to 45% (P<0.01). In these layers Mgdid not protect against cell loss but enhanced the effect ofPH as indicated by reduction in PV cell number to 20% (P<0.01). In the hippocampus PH did not affect the expression of GAD in the CA1 and in the hilus, though the number of PV ceils in the hippoca_.rnpus was reduced to 45% (P<0.01) of the control mce. This was not prevented by Mg (44.%, P-0.01). When the effect of Mg alone was tested we found an elevation of GAD in M1 layers 4-6 (P<0.05) and the _h_'ppoe..ampus (P<0.01, compared to control. In contrary, PV cell loss was observed in 111 layers 4-6 (P<0.01) and the hippocampus (P<0.01). Our data indicate that hypoxia inddced loss of PV cells without affecting GAD.Lack of effect on GAD could suggest that hypoxia induced an increase in inhibitory synapses .to Our results indicate that the PAs system is involved in axonal and myelin damage oeeur.r.ing d_urh.g EAE in CNS tissue. Accordingly, we suggest that the PAs .system may be a potential .target for treatment of CNS ififlammatory and demyelinating disease.
suggesting that one or more chemical systems additionally implicated in OCD are more directly related to the lateralized deficits. The relevance of the d0paminergic .system is discussed_ based on the nature of its involvement ifi the modulation of attention.
The infralimbic prefrontal cortex is required for consolidation and reconsolidation of object recognition memory Maroun M.', Dudai y.2, Akirav I. e-ffaTh tnd Behavior Research Center, University of Haifa, Haif_a 31905, Israel Dept. of Ne_urobiol_ogy, greizmann Institute of Science, Rehovot 76100, lsrael.; Consolidated memory could reain susceptibihty to consolidation blockers upon its reactivation. This process o.f destabilization and the ensuing restabilization of reactivated long-term memory is termed-reconsolidation. It has been shown that both consolidation and reconsolidation require protein synthesis, but it is not yet known how similar these processes are, in terms of m01eeular, cellular, and circuit mechanisms. Here we aimed to examine the role of infralimbie cortex (IL) in consolidation and reeonsolidation of object reeogni.'tion memo involving s.pymtaneous exploratory behavior of the rat. We found flaat the protein syiathesis inhibitor anisomyein and the N-methyl-Daspartate (NMDA) reeep.t0r antag0m_'st D,L-2-amino-5pliosphonovaleric acid (APV), infused in the IL tmm.ediately_ followh.g the reco.gnition train__g phase, resulted in failure to allcriminate between the old and new 9bjeet 24 hrs later. This indicates .that the drug treatments have disrupted consolidation oi-the reeog'tion tasl In contrast amsomyein and APV to the IL hd no effect on short-term mem_oDr. We also found that anisomyein and APV infused in tt/e IL immediately following reaietivation o.f the memgry trace by brief, ree.xp.osure, to the learned objects, result6d in failure to discriminate between old and new object 48 hrs later. Thus, the drug treatments have disrupted ree0nsp..lidatipn of l_ong.-te_r!n reeognia.'on mem.ory. Tlae present findings show for the lirst tittle tlmt the IL ts ne_eessary for long-term consolidation and reeonsolidation or recognition memory, and that both processes are d_epdent on protein synthesis and NMDA receptor The frontal cortex and striamm have consistently been proposed as possible sites of dysfunction in OCD, based on convergi.'ng evidence including neuroimaging sdies emphasizing abnormalities in neural loops conneetingthese .areas. There is increasing evidence attributing OCD to lateralized CNS pathology, but research is inconsistent with respect to which hemispliere is preferentially involved, and in what manner. The present s.tudy employed the Posner spatial orientation para21i_gm, which has been used to study lateralization in psychiati-ic and neurological cases, in an att_empt to exanunepatterns of lateraliz&l dysfunction in OCD. Seventeen OCD patients were compared with ten healthy controls on reactaon time and asymmetry measures derived from the paradigm. Comparisons were also carried out after subdividing the patient group based on .demographic and climcal data, to examine relationships_ between task performance and specific characteristics of OCD. Control s_ubjeets respond&i sigrdfieantly faster to targets in the left visual field than to those in the right, whde in OCD patients this asy_.metric pattern was ab.sent .or reversed, in line with earlier suggestions regarding lateralized pathology_ in OCD. The lack of asymmetry was positively correlate! with obsession severity, particularly for agessive and sexual obsessional content, supporting recent findings relating different symptom dimensions to distinct components of fronto-sh'iato-thalamie circuits involved in OCD. The altered pattern of asymmetrY was not related to medications influencingthe serotonergic system, PRS-211,375, a novel CB2 selective cannabinoid agonist, with neuroprotective effect in thre animal model ot" MS Meilin S., Margalit R., Richstein A., Weksler A., Berekovitc Y., Amselem S., Avidor B., Yaeovan A., Bar-Joseph A., David P. University, Tel Aviv, Israel; The exocotic process in neurons and neuroendocrine cells consists of a sequence of reactions between well-defined proteins. In the present study, we have, for the first time created, a comprehensive kinetic model that reconstructs the physiological process using a standard chemical kinetic forrflaIism. The interactions between the synaptie proteins were transformed into differential rate equations that, upon their integration over time, reconstructed the experimental signal. Tile model can perfectly reconstruct the kinetics of exocytosis, the calcium-dependent priming and fusion processes and the effects of genetic manipulation of synaptie proteins. The model suggests that ft/sion occurs fi-orn two parallel pathways and-assi.gns precis% nonidentical synaptic protein complexes to the two pathways. In addition, it provides a unique opportunity to sdy the dynanaics of intermediate protein complexes during the fusion proe,ess, a possibility that is hidden in most experimental systems. We have used the Genetic Algo_rithrn analysis to achieve high level of accuracy and to find a single global minimum, over a mult.i dimensional parameter space. Our study demonstrates that complex biological processes can be mathematically modeled and gain high predictive power, up to the level of serving as research tools. It is our intentmn to expand the model fi'om the level of a comprehensive description of the whole exocytotic process, to the level of cell physiology. Center and Sackler ,School ofMedicine, Tel-Aviv University, Tel-Aver 69978, lsrael; Cortical neuronal activity is highly variable even under tightly controlled stimuldtion paradig_ms. Previous studies in the monkey have found the Ievel ot" this variability to be on the same order of magnitude as the response itself. Therefore in order to reach sufficient signal-to -noise ratio numerous repetitions of the same stimulus are needed.
Hence, it may be inferred, that during complex and continuous natural stimulation this variabifity may even be accentuated. Here we report that surprisingly, single neuron responses recorded in the human temporal lobe durin g exposure to a popular movie, manifested a highly reproducible stimulus-locked modulation, with average correlations above 0.5. This r.eproducibility was apparent even when only two r.epetiton of the movie were compared. This high fidelity was particularly striking_ in human auditory cortex where the correlation between first and second movie presentation reached as high as 9.8. Although it may appear that such high fideli implies highly Iinear relationship to the acoustic stimuli, m fact the neuronal responses appeared highly non-linear showing particular selectivity fbr spoken words and musical phrases. Interestingly, the high fidelity of the neuronal responses was expressed only at temporal windows of 300 msec and higher. These results reveal precise reproducibility" of single neuron responses across repeated presentations of natural stimuli, but also suggest a hmit of"temporal graininess" of the neural code expressed by human temporallobe neurons.  (Weinstock, Stress 5: 167-176, 2002), our objective was to investigate the effects of gestational stress on the development of synaptic networks n the prefrontal cortex of rats and to clarify if the presumed svnapfic changes can be prevented or reversed by postnatal teatments such as daily handling of the offspring during the. first 10 postnatal days. By using the Golgi-Cox staining technique we quantified the density of spine synapses and dendritic length of pyramidal neurons in the anterior cingulate cortex (ACd) in male pups of the following experimental groups: i) prenatally-stressed (PS), ii) PS + postnatal handling, iii)nai've controls, iv) naive controls + postnatal handling. Our data indicates changes in the density_ of dendritic spines on basal dendrites and alterations in the length of apical dendrites between PS pups and PS pups, which were handled. Alterations in the length of basal dendrites were found in PS rats, compared to naive controls. The results of this study provide the first evidence that prenatal stress and handling interferes with the development of cortical dendritic spines and dendritic growth. These synaptic changes might be causally linked to the behavioral abnormalities, which have been described after prenatal stress and handling. Supported by Dl'G/SFB426. Are protein alterations in schizophrenia due to early environmental insult? Nadri C.',2, Agam G. ',2, Belmaker RH.
Both genetic inheritance and perinatal environmental insult contribute to schizophrenia manifestation. Recent studies of the etiology of schizophrenia concentrate on the genetics of aberrant brain proteins or on epidemiological retrospective studies of environmental insults. Little is known concerning the biological and physiological processes, such, as morphological changes, neural transmission and signal transduction, that mediate the environmental contribution. The neurodevelopmental hypothe's of schizophrenia suggests that an early life brain maldevelopment, predisposed and/or acquired, manifests the pathophysiology of schizophrenia later in life. Possible non-genetic risk factors for aberrant neurodevelopment are viral infection, starvation/malnutrition, stress, premature birth and perinatal hypoxia. A strategy to study the contribution of perinatal insults to schizoplirenia is by induction of a risk factor in an animal model. We chose to address the search for etiological factors of schizophrenia by combining the two distinct approaches that dominate the fiterature, namely, the role ofgenetically aberrant brain proteins and pennatal insult. We are focusing on four distinct rat models for schizophrenia and assessing brain levels of six proteins that were found to be altered in empiric studies of postmortem brain from schizophrenic patients. We hypothesize that the alterations in the levels of some of these proteins may reflect the contribution of environmental insults to schizophtrenia rather than genetic factors of the disorder. The magnitude of the contribution of binaural interactions to speech intelligibility as measured by the Binaural Intelligibility Level Dfference (BILD) is not well under(too& and, in contrast to speech detection, has even been estimated as marginal. We reasoned that the magnitude of BILD may depend on stimulus characteristics and" asked whether factors such as stimulus familiarity, inter-stimulus similarity and set size affect identification thresholds of speech m noise, under diotic vs. dichotic conditions. We tested 25 subjects under 8 different identification conditions that marupulated familiarity pf the stimulus set (digits versus pseudo-words), similarity (changes in a single phoneme or in all phonemes) and set size (2 or 10 words). We applied an adaptive procedure to measure thresholds for 80% correct identification when noise was in-phase in the two ears, and stimulus was either in-phase or anti-phase. BILD is the difference between these thresholds. Identification thresholds depended significantly on all tested factors. Thus, highest thrrsholds, were found for largest set, minimal familiarity, and maximal similarity (10 pseudo-words). The dominant factor for lowering of the threshold was similarity, while set size (2 vs. 10) was the weakest factor. On the other hand, the magnitude of BILD depended only on inter-set stimulus similarity, with no effect of set size or familiarity. Very small BILDs were found when stimuli wereperceptually similar (3dB), whereas up to 9dB were found when word pairs were very different. Taken together, our results show that all 3 factors examined affect absolute identification thresholds of speech in noise. On the other hand, the benefit f binaural cues may be rather small, as previously cumented in the literature, depending on the structure of stimulus set. Surprisingly, however, quite large binaural effects were found when stimulus set consisted of words that differed along multiple perceptual dimensions. Similarly, EN 101 decreased human T-cell reactivity toward mitogens and TNF-\ production, whereas IL-10 production was unaffected. We have examined the efficacy of_bifunctional compounds containing nonsteroidal antiinflammatory drug (NSAID) and CURE moiety (pyfidostigmine, AChE inhibitor)r in EAE model in mice and obtained a significant reduction in clinical symptoms and T-lymphocytes reactivity. The bifunctoonal compo,unds IBU-PO and IBU-PD (Ibuprofen Octyl (or Decyl) Pyridostigmine) were tested in vitro in lymph.bcytes and astroees and inhibited dose-dependently at micromolar levels production of inflammatory mediators (nitric oxide and prostaglandin E2). The contribution of each component of the bifunctional compound to the attenuation of inflammation was evaluated. It was noted that both moieties could suppress lymphocyte reactivity to a lesser extent than the bfunctlonal compound. Thus, bifunctionals act synergistically compared to their components. Inflammato mediators pr6duetion was not affected by AChE inhibitors alone yet bifunctional compounds augmented the anti-inflammatory effect of the NSAID moiety. Our data are consistent with anti-inflammatory_ activity elicited by the ChEI moiety only when it resides in the bifunctional molecule.

Features of Human Movement Imitation
NoL., Flash T. Dept. of Computer Science and AppliedMathemancs, Weizmann Institute 9f ciqnce' Human movement mtaton s a complicated phenomena, involving a transformation from perceived to ex.ecuted movements. What are the features of movement that are being extracted and used in this transformation? We developed a novel experimental scheme to tackle this question using virtual movements. Two setups were developed along this scheme for arm and finger movement imitation. Using these setups, we investigated the hypothesis that observed movements are automatically mapped to the corresponding motor representation (the 'direct matching' hypothesis). We tested the 'direct matching' hypothesis-by manipulating the orientation of observed movements, using several forced-choice tasks. In these tasks subiects had to perform one of two movements (for example Iifting the index or the middle finger), as quicldy as possible, in response to the same movement of a virtual hand. We found an orientation effect (longer reaction-times for stimuli that are ftmher rotated from fhe executing hand) in some tasks (e.g. ling one of two fingers) but not in others (e.g. operiing or closing of the hand). Based on these resultg, we claimed that in forcedchoice imitation t.asks subjects do not map obsery_.ed movement into their own movement repertoire. We h_ypothesized that subjects extract simple, task-related f.datures of the movement, for example, the appearance of the movement on the left or the right sides, m order to choose the app.ropriate response. By introducing another task, where subjects had to Iift either their left or right arms in response to movements of a .rotated human figqr_e, we managed to directly contrast the two at.counts for the transformation from perceived to executed movements in forced-choice imitation tasks, and to provide support for Dept. of Anatomy and Cell Biology, Hebrew University Medical School, Jerusalem 91120, Israel; Ion channels were originally defined according to their mai.n mode of gating as; voltage-gated, ligand-gated, echano-gated. and volume-related ion chahnels.
ttowever, studies in recent years have demonstrated that ion channels may be gated, or regulated, by more than e modality. For example, it is well established that the activity of calcium channels can be regulated by a variety of ligands (neurotransmitters, G-proteins, protein kinases etc). In addition, recent studies have inted to the possibility, that voltage-gated calcium channels are osmosensitive or mechanosensitive. We examined the possibili that voltage-gat calcium influx may be regulated by .alterations in cell volume. Our studies have shown that voltage-gated calcium influx in pitui"tary cells is suppressed by osmotic induced cell Shrinkage, and augm .ented by osmotic induced cell swelling. In a series, of control experiments we ruled out the possibility that this reg.ul.atio.n of .calcium influx, by cell-volume, can be atfriuted to alterations in cell membrane surface area (during cell shrinkage and swelling), to actiyation or inactivation of other onic conductances or to changes in access resistance. Additional experiments have shown that this volume dependent regulation of v.oltage-gated calcium channels stems from alterations in the activity (NPo) of calcium channels but not from changes in single channel conductance. However, whether these changes in activity stem from changes in open prqbabili (Po), or from changes in the ninber of channels activated -_(hi), is still unknovn. Hence, our results suggest that voltage-gated calcium channels in pituitary cells may also be considered as volume-regulated on channels. The cellular mechanisms underlying this regulation are unknown yet. However, it is possible that alterhtions in mechanical membrane tension, or alterations in intracellular iomc strength, are involved in this regulation.
Tracing the affective modulation of cognitive brain .activ!ty with electrophysiological functional brain magmg OfeK E. and Pratt H.
EvokbdPotentials Laboratory, Technion -Israel Institute of Technology; Rationale: An experimental paradigm, was designed to study the exact time course of the emotional modulation of cognitive brain activity_. Brain activity related to emotional and cognitive processing has been typically trace.d with fMRI's temporal resolution of seconds-. In this Study, the time course of activation in the brain areas involved was traced with millisecond temporal resolution. Methods: EEG was recorded while 12 normal subjects performed an auditory cued attention task., in which cues, m moot cases accurate, provided informataon on the appropriate response to a subsequent target tone. Verbal distracters, admimstered at different times between the cue and the tget in one third of the trials, were first names. Distracters' subjective affective valence was assessed after the experiment using a validated questionnaire designed for that purpo_se. Evold potentials to the targets were averaged according to the preceding cue's validity and the aff-eetive valence of the distracter. Potentials were averaged across different onset times of distraeters, so that brain activity was locked in time to the targe but not to the distractes. Brair_ sources of scalp electrical activity were estimated time flame by time flame, for the 800 ms after target ons.et using LORETA. Statistical comparisons were _c0nd.ucted.m ordei" to assess the effect of the distracters" affeetive valence on brain activity to the following target tones. Results: B.r.
res.porke, to targets was enhanced following distracters wi sutijective atlbctive valence, compared to neutral distracters. The distinct activity pattern involved prefrontal cortex, secondary audiry cortex and limbic system association areas, depending on the subjective_emotional significance of thd preceding distracters. iummary: Processing of neutral tones was modulated by the subjective emotional significance of preeedin_g distraeters. Here we report the pr_e of CB2 receptors in trabecular, diaphyseal _and 191C3T3 _El ooteoblasts.as well as osteoelasts. Reminiscent of post-menopausal _os.teopor.oois in humans, the skeletal phen.ote of CB2 deficient mice, which are otherwise normal, s characterized by a low trabecular bone mass, cortical expansion and increases in bone formation rate and osteoclast number. To extrapolate these findings t9. the human scenario, we performed ge.nec association studies in a ease-control approach typing single nucleotide pqlyr0orphisms coveringa region 6f abbut Y00 kb. We fouhd a highly significant ilifference of allelic and genqtypic disb.qfigns, strgn.g.ly arguing for a .ea_usa.t.ive mvolvement of this locus with human osteopoross, tn hne with the low trabeeular bone mass phenotype of CB2 knockout mice we found that HU-308, a specific CB2 ag0nist, stimulated dose dependently the humber and activity ofprimary and MC3T3 E osteoblas.tie cells. Us.'mg the same dose range, HU-308 also restrained oste, last differentiation of bone marrow derived monocytes. Most importantly, HU-308 attenuated qvarieetomy_-induced bo.e loss mainly by inhibiting osteoclast numbs. Collectively these results assign a skeletal regulatory role for the endocannabinoid system and offer a new molecular target for the diagnosis arid treatment of osteoporosis.
The metabotropic glutamate G-protein-coupled receptor mGluR3 fi voltage sensitive.
Ohana L., Parnas I., Parnas H. '-fOtLoew Minerva Center for Cellular andMolecular Neurobiology, Hebrew University, Jerusalem,; G-Protein Coupled Receptors (GPCRs) co.mprise the largest su.pan.ily ofprot.eins m mamm_alians andplay a k iole in signal .transduction processes. In spite of GPCRs bei.ng transmembrane proteihs they are not considered to pe voltage sensitive. Recently it was shown ..tt me muscirinic M2 receptor is voltage, sensitive. Here we examine whether a metabotrgpie glutamate receptpr, a GPCR, exhibits voltage sensitivity.-Using fresh rat t}rain synaptosomes we show that. presaptic glutamate receptors bind glutamate in a voltage de.pendent manner. Namely, Depolarization reduces the magimal binding of [3H]GIu. Pretreatment of the synaptpsomes with Pertussis Toxin (PTX) reduced the [3HIGIu binding altogether .and greatly diminished its voltage dependency, indicating that the voltage dependent binding c6uld be attributed to PTX sensitive metabotropie glutamate receptors. We used the heterologeous expression System of X_en0pus oocytes to directly study the properties of mGluR3, a presynap_ti receptor, and a member of the mGluRs of group II. mGluR3-mediated potassium channel currents were used.to assay the activity of the receptor. We found that the apparent affmi'ty of mGhR3 towhrd glutamate was redue.ed upgn depolarization. We ruled out the possibility that the voltage sensitivity_ resides in steps that are downstream to the activation of the mGluR3 by glutamate.. Our cumulative results are. compatible with the notion that the mGlul.3 exhibits, y itself, vol_to_ge sensitivity. In addition, the fraction of the high. aff'fffity receptors was significantly reduced in ooeytes that did not overexpress Gal-pha. This, toge_.ther with the abolishment of the voltage dependent b.ifiding in syneptosomes in the presence of PTX ihdieates that th voltage sensitivity may reside in the region that couples to the G-protein-Furthermore, analysis ofthe time course of mGhng3-mediated K+ currents reveals that depolarization affects the Koff ofthe receptor. Nu. bers are represented in sym_bolie (Arabic & verbal) and _alog magni.'iude format. Reflecting these formats, different, pa/'tially., overl_apping, represenfations are found in parietal cortex (PC;lhaene et al., 2003). How are continuous uanttties, such as size and luminance, encoded in the brain. It has been hyp.othesized that a single system in PC represents both the fibove-mentioned non-sy.-bolie analog rium_bers and an abstract .ep.d.e" of. eoritin.uou.s qthgn,tities. llais system is seen as a high-level magmtude estimator that p/oduces the abstract value of a scaled magnitude and fiaakes __ti.'s value available for. the cogt_fi_'tive or executive system. We tested a first prediction of this hypothesis: that this re.gion should respbnd to a .quantity vhlue (e.g. object size) irrespective of the modahty that sees it (visual or somatosensory), when the value is. readout by the hand movement system and re-represented in terms of a corresponding amplitude of graping-like finger movement. We applied a blqck-design&l fMR] test (1.5. T; EPI). Three shbjeets, evaluated e size .(main condition) or surface texture (control) of different 9bjeets presented visually or exploredhaptically with the left liand. Then, by uniforinly moving thetr riglit thumb and index .finger on the surface of a texture21 sheet, th_e.y_ either indicated the size of the object (main condi,fion) or compared the sheet texture with that of the object (control). We obtained differential fMRI signals (m/tin condition minus control) in left intraparietal cortex and the superior parietal gyrus, areas ovtrlapping the analog nfanber representatmn. These prelimiriary lata support the above h3pothesis, that a single system represents both analog timbers and continuous quantities. stress can alter the densitiV of dendritic spines i.n. pre.ty_ ont.al cortical and hippocampal areas. In order, to idtntity the cellular mechanisms for this synaptie plasticity a spine-rOdueing protocol in cultured hippocampal neurons ldin et aI2001 J Neurosci. 21:186) was usdd to measure 6__han.ges of size and shape of new and old soines. lmrthermore, .presynaptic s.true.tures on novel _and ."'old:' spines were characterized. Single neurons, transtected with GFP were immunostained ad embedded for electron microscopy. CLSM analysis revealed that a total of 1.524.0.10 spines per 101am dendritic segment (n=18 cells), 0.944-0.08 (i52%) were 'old' spines, i.e. spines which were found both at the beginnirig and at the end of the experiment, 0.584-0.05 were novel spines, and 0.194.0.03 .spmes/108m were lost during the experiment. After id.enti.fi.cafion of the spine-pr-oducipg neurons in .the ultrathin sections the images of serial sections were taken with a CCD camera attached to the electron microscooe LEO 912. After alignment of serial sections using SEM software, some neurons and segments were 3D reco,nstrueted using IG.L softwar_e and D Studio .Max".. As result we found tlfat the ratio of novel spines with/without_ presxn,aptic structure was 69"./d36 %0, i.e. the majority novel spines was contacted by at least one presynaptm structure. The ratio of"old" sp)lies witl#,with..out, presmaptic structures was 55/d45 %), in'dicating that a little .more than half of the pre-existing sprees resemble functional synaptic structures alter the spifie-creating protocol.
Supported by a grant from the VolkswagenStiflung to MS andKB.
Brain activation of dominat vs non dominat band areas during linguistic activityan fMRI study PaltiD.% Hadar U.' 'psychology Dept., Tel Avv university.; The Wohl Institute for AdvandImaging, Tel Aviv SouraskyMedical Center.; In this stu_dy we wish to investigate the connection between language ftmetions and the motor system by comparingthe dotainant and non-dominant hand areas during lingfiistic activity. We present here preliminary results from s.even fight-handed fiative Hebrew speakers that were scanned in a 1.5T GE scanner during two e_xpei_'mental sessions. The first exp_riment was comprised 0f motor linguistic tasks Within a block designed experiment. Motor tasks inehded simple movements of righi and left hands for _all subjects and s'.maple movements of righ[ and left feet for thrde of the subjects. The linguistic task comlrised of a covert association generation to a given noun. We used the neuronal activi_ty during movement pef.'od_ in order delineate the primary motor areas of the hands and feet and then examin the relative neuronal activity (BOLD signal change) in these regig.ns during the free association task. Across s.ubjects, the fight hand area showed a s_ignificanfly inereased_sgnal than the leR hand, and this diffdrenee was not significant for the fight and left feet..in the second e_ent the same subjects were asked to listen to a st_opy for 6 minutes. Based on the regional def'mitions from thi first experiment we correlated between the time courses in the motor areas and the time course in broca's area throughout the sto. The results showed that the ,right hand area was significantly more correlated with broea s activity_ than the left hand area, but no such difference was observed for the feet areas. These results suggest that the neuronal mechanisms related with language functions and hand manipulation may share a common neuronal system. We reported that closed head inj_uy_ (CHI) in mice causes a sharp elevation of brain 2-aracliidon0ylglyeerol (2-AG) levels, and that exogenous 2-AG reduces brain edema, infarct volume and hippocampal death and improved clinical recovery after CHI. 2-AG robustly reduced CH.Iinduced dis_ruptmn of the blood brain barrier (BBB) at and abolish&t the 3-4 fold increase of NF-kB transactivation, at 24h aRer CHI. Proinflammatory eytokines such as TNF-a, IL-lb and IL-6 are known as NF-kB inducers. TNF-a is also one of the major promoters of BBB disruption after CHI. CHI was caused to Sabra mice and mice were sacrificed at 2 timepoints after injury: 2 and 4 hours. Total RNA was extracted and RT-PCR was house-keeping gene and cytokines expression was evaluated against b-actin. TNF-a was undetected in untreated ammals and CHI caused to massive release which was partly inhibited by 2-AG treratment at 2h but not at 4h timepoint: 113.43 vs. 84.15. IL-lb level at 2 and 4h was the same and 2-AG caused to decrease of IL-lb level at 4h: 124.22 vs. 103.52. IL-6 level at 4h was higher than at 2h and 2-AG treatment led to decrease in IL-6 level at 4h: 94.01 vs. 67.06. Conclusions: TNF-a, IL-lb and IL-6 levels increase short time after brain _injury in mice and this subsequently lead to BBB disruption and NF-kB transactivaton. All these detrimental effects inhibited by endogenous cannabinoid 2-AG.
Loewenstbin Rehabilitation Hospital. Raanana; kSackler School ofMedicine, Tel-Aviv University, Tel-Aviv; 3Dept. of Neurobiology, Brain Research, The Weizmann Institute Of Science, Rehovot; Cases in .which a. unilateral spatial neglect (USN)atient is able to detect the stimulus on the neglected sle when.
presented unilaterally, but fails in the case of .bilateral sttmulation, are termed "extinction". This extinction effect is very common in USN patient.s, andhas a large impact on their everyday life but its relation to the main neglect syndrome s ILoorlv'urderstood=Here we asked_whether the extinction etlect" is a.sp.ecitic, property or-the USN syndrome or alternatively it is due to th6 low saliency of the stimulus presented on the left, making the extinction e.ffect a. natural consequence of neglecf. Three. braindamaged.patients with USN and 4 normal controls, were given a detection task us'_m_g Gabor patches presented on a computer display with different eccentriciti. Following a contrast calilSraton stage where we measured the detectxon threshold at each side we set the stimulus on one side at its contrast detection reshold, and used multiples of that threshold on the other side. We then tested performance on. a stimulus detection task with interleaved trials of unilateral and bilateral simultaneous stimulation (BSS). Both USN patients and controls showed extinction during BSS, i.e. made more errors in deteetin the weak stimulus when one side was set at contrast .thres'hold level, thus co.mpensating for.possible attenuation due to USN. Howe.ver the patients and controls differed in their sensitivity to the contrast level of. the ext.ingu.ished stimulus. While a 1.5-fold increment eliminated extinction for the controls, a 2.5-fold increment was needed to release a stimulus from extinction in the USN patients. We conclude that the extinction effect in contrast detection is, in part, a natural consecluence of the low saliency of the stimulus on the neglected side, but i.s more severe for the patients, suggesting an additional extinction-scific deficit. Ths extmction-slecific effect could be a robust measure and used for clinicaldiagnosis. proposed for a neuroscientifie-oriented clef'tuition of mental disorders. Plasticity refers to all brain processes involved in dynamic alterations within communicating ne,uronal ensembles or networks, in the brain. Complexity refers to certain formulations from system theories relevant to brain dynamics. Plasticity processes are divided into three es based on time domains, t) "developmental plastici,ty, 2) "tuning plasticity" and. 3) 'fast stabilizing plastieit,y.' Each type ofplasticity is related to different complexit3 models achieved by the brain. Mental disorders can be reconceptuahzed as disorders of plasticity resulting in disturbances of state-space brain cohfiguratmns, matching and neural eomplexittes. The new neuroseience-oriented diagnostic system generates testable predictions regarding diaggosis and treatments of mental disorders, which may be the future science for psychiatry. The voltage-dependent M-type potassium current. M" current) plays a major role in controlling brain excitability b_y stabiltzing the membrane potential and acting as a brake f6r neuronalfn'ing. The KCNQ2/Q3 heteromfric channel complex was identified as the molecular correlate of the Mcurrent. Furthermore, the KCNQ2 and KCNQ3 channel subunits are mutated in families with benign familial neonatal convulsions, a neonatal form of epilel:. Enhancement of KCNQ2/Q3 potassium currents .may provide an important target for anti-epileptic development. In this study, we synthesized noel KCNQ2/Q3 channel Ol.ners, derivatives of Nphenylanthranilic acid, using meclofenamic acid and, diclofenac as primary templates. External application ot these molecules in the micromolar range results in activation of KCNQ2/Q3 K+ currents, heterologously expressed in Chinese hamster ovary (CHO) cells.-These 0_leners activate KCNQ2/Q3 channels by causing a lftward shift of the voltage activation curve and by markedly slowing the deactxvation kinetics. SAR studies revealedthat the pharmacophore of the newly synthesized N-phenylanthranific acid series includes esters or secondary anudes derivatives with a terminal hydroxy group. Thus, the novel molecules increase KCNQ2/-Q3 current amplitude at physiologically relevant potentials and lead to a hyperpolarization of the resting membrane potential. In rat cortical neurons, they inhibit bbth evoked and spontaneous spiking activity. These derivatives of N-p.henylanthranilic_ acid constitute novel drug templates for the treatment neuronal hyperexcitabilit, including epilepsy, ischemic stroke, migraine, and neuropathic pain.

47
The role of LPAI in formation of synapses among cultured hippocampal neurons Piloel Y and Segal M. e_-pt. Neurobiolgy, The Weizmann Institute, Rehovot; We studied the lysophosphatidic acid receptor-I (LPA1R) gene which we found to be expressed endogenously in cultured hippocampal neurons. Overexpressed GFP-tagged, membrane-associated LPA1R accumulated in a punctate manner over the entire dendritic tree and caused an mcrease in dendritic spine density. About half of the spines in the. transfected neurons displayed distinct LPA1R puncta, and this subset of spines was also substantially larger than puncta-free, LPA1R transfected or control GFP spines. Exposure of LPA1R transfected cells to LPA caused a rapid (< I. 5 min) aggT_egation of reeeptors into endoc otic puncta,.. which were ihen rapidly transported along the dendritic cytoplasm. Finally, vhile spontaneous mimature synaptic currents were of the same amplitudes, they decayed slower _ha_ LPA1 transfected neurons compared to GFP controls.
We propose that LPA1R can re.gulate local morphological plasticity of dendritic spines in cultured hitJpocampal neurons. Vasoactive intestinal neuropeptide (VIP) provides neurpprotection through binding to high affimty receptors on ghal cells that activate increases in the production and release of survival promoting proteins. Three VIP binding sites that belong,to a subfamily of 7 trans-membraneang G prote,n _cpUp_led receptors have been cloned: C1, VPAC2 and PAC 1. PAC1, while recognizing VIP at a very low affimty, recognizes the VIP-related peptide, pituitary adenylate cycl'ase activating polypeptide (PACAP), at a very high affinity. Six different splice variants in the third cytop[asmatic loop of the PAC mRNA were isolated. An antisens oligodeoxynucleotide specific for HOP2 (a splice variant of PAC1) kills neurons re'cell culture, and reduces VIP binding to glial cells. Thus, HOP2 is implicated in VIP-mediated neuroprotection (J Mol Neurosci. 1997;9:211). The aim of the_present work was to examine the affinity of the cloned HOP2 receptor to VIP and its analogues. The PAC eDNA was PCR-cloned from rat cerebral astrocytes and genetically manipulated to obtain the HOP2 splice variant. It was then inserted into an expression vector and transfected into COS-7 cells that were used for 125I-V1P and 125I-PACAP binding assays.

Temporal properties of collinear facilitation
Polat U.I Sagi D? q'el-Aviv University: Faculty of Medicine, Goldschleger Eye Research Institute, Sheba Medical Center; Dept. of_ Neurobiology/Brain Research, Weizmann Institute Of Science, 76100 Rehovot. Israel; Visual masking refers to impaired performance on a target stimulus when a mask stimulus is presented for a brief presentat!on time before, during or after the target presentation. However, the threshold for contrast detection mproves when a target is presented with two collinear flankers (Polat & Sagi 1993). Facilitation is found when the target is presented smultaneouslywith the flankers or with a delay (Tanaka & Sa 1998). Here we test the temporal properties of lateral facditation by manipulating asynchrony of both onsets and offsets of the target and flaTnkers. In the experiments, the contrast threshold for a Gabor target was measured in isolation or in the presence of two collinear Gabor masks using a 2AFC staircase method. Experiments were carried out where the mask (60 ms) was presented before (Forward Masking: FM, isi=60 ms), simultaneously (SM) or after the target (Backward Masking: BM, isi=60 ms). The results showed target facilitation, 0.15-0.30 log umts, (I) for simultaneous target and mask presentations (SM) with all durations tested 60-320 ms, (2) when the maskpreceded the target (FM);but (3) not when the target preceded the masks (BM), where some suppression at 3 lambda was observed instead. Additional e_xperiments showed that a second pair of masks presented after SM (isi=60) cancels the SM facilitation. This pattern of results implicates a long integration time for lateral excitatory effects. The results point to the existence of a neuronal network with slow excitatory, processes that are activated by low contrast inputs (tar.ge.f) and fast inhibitoryprocesses that are activated by high contrast inputs (flankers).
Presentation of the maskers after the offset of the target reinforces the inhibitory effects.
Generation of peripheral sensory-like neurons generated from human embryonic stem cells we designed a psychophysieal training, procedure on humans that captures these association effects on memory of faces. Subjects were trained to recognize a set of faces.
After the memories of the faces were confn-med by an identification task, subjects repeated the identification task on various faces, including a se_quenee of stimuli gradually. transforming between a parr of fiices from one memorized face to another initially distinguishable face (morph sequence). For each sulsjeet, this task was repeated in multiple daily sessions on the same pair of fiices. This protocol led to a gradual change in identification of the morph sequence by more than half of the subjects, eventually resulting in wrongly remembering the two pair faces as the same one and to an increase in their perceived similarity. A critical parameter for this effect to take place was the extent to which the subieet initially distingmshed between the pair faces (faces that seemed-very different initially, stayed distin_guishable; faces that were perceived as different but more similar, eventually were remembered as one). A similar procedure, with the exception that at every session the morph sequence was presented in a random order did not yield any significant change in identification, recognition or similarity of the two pair faces. These results show that long-term memory of perceptual objects can be dramatically modified, up to the point where two different objects ard remembered as one. We show an attractor-based neural network model of associative memory that supports this experimental result. There is accumulating evidence that the visual cortex .is adaptable when. deprived qf its original input. We recently showed that the occipital cortex of congenitally blind subjects is .activated dtiring tasks requiting verbal-memory processes. Activation was found in regions corresponding to retinotopic visual areas of sighted, including th calcarine stilcus (V1). No such occipital activation was found in the sighted. One year later the same blind subjects participated in a second fMRI scan, to study the contribution of semantic elements and episodic memory in the occipital activation. During the current scan, subjects p.erformed an episodic memory task, requiring them to dentify words that were originally presented m the first scan. We demonstrate here that the magnitude of V1 activation during this task is correlated with onlhe memory performance. During the current scan, recognition-memory, performance differ&l signifi.eantly between two sets words due to extensive practice on one of the sets prior to the previous scan. Across the blind the better-remembered set of words elicited greater V activation than words from the poorly-remembered set, although the semantic components and the behavioral task were similar in the two sets. This indicates that activation in V1 of the blind is associated with long-term episodic memory, on top of semantic processing as suggested previously. Furthermore, within the blind subjects, those who showed better recognition-memory pei'formance demonstrated greater V activation compared with the poorer _performers. These results suggest that in the congenitally blind; the posterior occipital cortex (including V1) may be involved in episodic retrieval.  (BA 17,18,19,21,31. and Hippy.ampus). Thus, compared to grouping into staalm, grouping mto an orientation is associated, with hig..ei activation in different brain areas albeit with an initi.ally longer latency. Interestingly, this activation did not induce awareness of'the grouped pattern.
Mapping descending pathways related to atonia and antifiociception during anesthesia geiner K., Sukhotinsky I., Devor M. To that end, rats were exposed to 1, 3 or 7 pairings of tone and shock. We found .th.at higher uber of tone and shock oairings restated in more resistance to extinction of fear. Next we aimed to examine whether expos.ing the rat to out-of context stress orior to extinction traimng would also affect the kinetics of extinction of fear. We t"ound that animals exposed to the elevated platform stress p.rior to extinction. field response and a parasagitally oriented optical response. In these cases the wdth of'the parasagital Band of activity was 300 im and its length was stimulus intensity .dependafit ranging from 400 im to more than 1200 ira. Activity w always synchronous _t_t_toughout the parasagital band with an average delay of 1.5 ms. The average rise time was ms and the average response duration (at half amplitude) was 26 ms. These fmqmgs are in agr.eement wth previous m.orphologieal and electrophysi61ogical analyses. The characterization of the c.limlfing fiber response enabled us .to study the spatial distribution of the long term interaction between the climbing fiber andparallel riser input.s, 1. own as cerebellar LTD. We found that conjunctive stirulation of climbing fibers and parallel fibers at a rate of 2 l-Iz for 50 s reduced-significantly the respo_ses to parallel fiber stimulation. Tiffs reduction was confined to the area where the two responses overlapped. .The magnitude of EEG waves at the alph_a (-10 Hz) ran.ge durinR rest and the Event Related Desvnchronization (ERI during visual and mental activity are both known to be correlated-with verbal intelligence. Previously in our lab, a positive correlation was found between subjects" intelligence score and their contrast sensitivity (CS) to 10Hz-flickers. Combining these two lines of researcl we now .asked whether the magnitude of alpha waves at rest i.s correlated with behavioral"CS tel0 flicker. Our initial findings (n=9 students) show a significant corr_ela.tign (r--0.76, p..05) between the relative pr.n ot a.lp.laa power and contrast sensitivity. Finding that aiplm magqitude is corrlatl _with_ behavioral s/tivity, we now asked, whether we can further increase alL.a magnitude .at rest by. exit.sure to 10Hz flicker. Stibjects passively watched int6rleaved series of 2-see flickers of 5 and t0Hz, 51 at both low and high contrasts for 30 minutes during which their EEG activity was rcorded. Th.eir b'havioraq .CS to 10 Hz flicker and their aloha magnitude at rest were both measured before and after this passive viewing.
Preliminary results show larger ERD in the alpha band fSr high compared with low contrast flickers during exposure, anl a tenlency for an increase in.relative alpha magnitude at rest. These findings suggest that we can behaviorally increase a person's alpha power, and yield the challengi.ng questio,n whether such an increase would impact the persons cognitive skills. In a varie.ty of species memory consolidation followi.ng different learning paradigms has been shown to be de.pendent on protein szntfiesis. Howev.er, it is not "knowq.
whether modulation at-protein synthesis is a critical c?mponent of the consolidation process, not is the identity .o.t any protein(s) subject to translational regulation known. W.e report_ here that phospholation _of edl.aryotic. e.longatlon tactor-2 (eEF2)., an indicator or translational elongation attenuation, is correlated ith input that produces taste memory consolidation in the relevant cgrtex.
The temporal pattern of eEF2 phosphorylation is similar to .ERKII activati.on and p70 $6 linase phospholation, known to stimulate translation initiation. In addition, eEF2 increased phosphorylation and /NCaMKI.I increased expression during memo.ry consolidation are detected in a syna.ptoneurosom.al fraction .made from taste coqex. The results suggest that increased initiation rate together with de.creas.ed elong.a.tion rate, during memory co.nsolida[ion, shirt the rate limiting step of protein synthesis tram initiation to elongation, to prbduce a local swtch-like effect in the expression of neuronal proteins.
Learning-induced reduction in predisposition for LTP: a possible mechanism for protection against runaway synaptic strengthening Saar D., Barkai E.
Dept. of Neurobiology and Ethology and Center for Brain and Be-ahvior, (hTiversity ofHaiJh; We studied the relations betwee.n learning-induc..ed modifications in the stren,th of s5 ,naptc co_nnectiwty and n. the threshold for LTP and'LTD induction. Rats were trained in an olfactgry discrimination task to distinguish between. positive and negative odor cues tmtil they demonstrated rule learning. Eearnin.g-induce.d cellular "and molecular modifications were sulgse.quently studied in the pirifo.rm cortex. rwo types of cellular modifications appear one d.ay after, lea'-ng: enhanced neuronal excitability, which is the result at-reduction in an intrinsic potassium current (Saar an.d Barkai 2003) and reduced predisposition for LT,P induction (d increased p.redisposition f6r LTD induction). .Background: While the arnyloid plaques pathology has been intensively investigated in the last decad6, the neurofibrillary tangles(NT), the AD component which correlates better wth dementia, has only recently been investigated in animal models. A few mutant tau tg animals have been created recently, presenting NT with a clinical phenotype varying from no neurological deficits at all, to some-lte-onset behavioral deficts, and to non-AD characteristic motor deficits, including paraparesis.
Design&Methods: 1. We introduced, into the tg tau gene, two pathogenic mutations[P301S;K257T] associated with severe phenotypes of tauopathy in humans. 2. We used the originaltau promoter, in order to express authentically the tau protein and avoid neurological deficits not characteristic to tauopa_thy or AD. Results: The tg-mice generated by us express the human double mutant tau in the hippocampus and cortex. At 6 months we detected argyroptfilic intracellular inclusions in neurons in the cortex and hippocampus by Gallyas-staining. Presence of NT was coiifirmedby immunohistochemicalanalysis. As early as 5-6 months the mice showed a cognitive deficit in the eghtarm maze and morris water maz,ej with no irrelevant motor deficits at-least till 18-months. Conclusion: We generated mutant tau tg mice presenting NT in the cortex and hippocampus, with an early-onset cognitive deficit and w.thout any motor impairment. These mice provide an authentic animal model for tauopathy and AD, within short time-frames. Prenatal stress in rats has been shown to reduce neurogenesis in the hippocampus and increase the size of the lateral am.ygdaloid nucleus. These structural alterations are associated ith deficits in spatial menao.ry, hyperarxie.ty d dep_ressive beh.aviour. The present stu@ eamined thb et-tect at-gestational stress during the last week of gestation in Sprague-Dawley rats on tlie length and d_ensity at dendritic spines, and on genes related to syo.apse tormation and activi in the hippocampus and cortical areas in 21 day old male offspring. Spatial and episodic memo_ry was assessed in adialt lttermates (3-4 months) by the Morris maze and object recognition tests respectively. endritic mgrphologv was assessed by m's of Golgi-cox staining, and gene changes by the Affimetrix microarray (8 samples, x 19,000 genes' each), followed by RT-PIR.. r'renatal stress caused a significant decrease in spine length and density in the orbitoltontal and anterior eingulate cortex. In the hippocarnpus, 2.4% of the enes were markedly reduced, the largest gro.up of which included components, of neurogenesis and syn.apse formation, activity and trafficking, such as comple.xin and 2, endophilin-1 and PSD-f5/SAPg0-as.sociated protein-3. The stud shows for the first time that prenatal stress can int.ertere with synapse formation, in the hipp_ocampus and reduce synapti.c connectivity in the cortex. These cha.nges e present at the time of weaning and pro.bably result trom .altered neuro.nal proamming of'the ftetal nervous system by maternal stress hormones like corticosterone. The sfi-uct.ural changes in the hippocampus and cortex contribute to the deficits in behaviour and memory seen in adulthood.

52
The Significance of Impedance Profiles of Pacemaker Neurons in Frequency Regulation of the Pyioric Rhythm Saraf-Sinik I., Manor Y. ept. ofLife ciences and Zlotowski Center for Neurosciences, Ben-Gurion University, Israel; Autor_hythmic neurons show impedance profiles that keak at a. frequency, called the resonance frequency, often close to their ntrinsic oscillatory frequency. When such a neuron is embedded within a network it is subject to electrical and chemical synaptie inputs which can affect the _cycle frequency. According to the impedance profile of the neuron, inputs coming at certain frequencies will be more important than others. Hence the impedance of a neuron ttmt p.artieipates in the_ production ofa rhythm, may be a critical component ot the mechanism by which cycle fr. e.queney is stabilized in the whole netwo. We examined this question in the pyloric circuit of Homarus americanus, which produces a robust oscillation (cycle frequency fpyloric 1Hz). We focused on neurons ofthe pacemaker group, the pyl0rie dilator (PD) and the anterior burster (AB) neurons. In the isolated neurons, we recorded the voltage responses to intracellularly injected sine waves of different frequencies. Since the responses to negative and positive currents were not symmeff'ical, we measured two different curves for the impedance profile: Z-(f) and Z+(f), r.espeetively. We found that the PD and AB neurons have ch.aracteristie impedance profiles not shown by _any other pylorie neuron: m the phcsiological range (f<3 Hz) Z-(f) was almost flat; at low frequ_ences, Z_f) increased with f andpeaked at fpeak=0.27+-0.12 Hz. At higher frequencies Z+(f) strongly decreased with f decaying belowZ-(f) at f>0.7+-0.2 Hz. Hence, at low quenees, Z+(f)>Z-(f) and therefore depolarizatory inputs are favored over h_yperpolarizat0ry inputs; these relationships are reversed f6r f>0.7 Hz (N=22). Thus, we hypothesize.that when cycle frequency transiently decreases blow, or increases above, .fpyloric depolarizatory (e.g., electrical coupling) or )/le_rpolarizatory (e.g., chemical inhibiry) inputs are differentially weigl_ed such that the cycle frequency is brought back to fpyloric. Understanding the physiology of any electrically excitable cell requires describing the k-inetics and membrane density of the voltage-gated .ion changels it expressed. The calculated conluctance densities obtained by us (Korngreen and Sakmann, 2000) and by others (BeIckers, 2000) to nstruct a compartmental simulation describing the firing of neocortical pyramidal neurons we discover that the estimates we obtained from nucleated patches and from cell-attached and outside-out patches were smaller than those required to reproduce the physiological firing pattern of the neuron.s. In oder to produce a reahstic si.mulhtion the somatic conductance density_ of voltage-gated potassium channels had to be several fold higher than that we have measured. To address this conundr6m we develgped a new techmque that correct space-clamp distorted voltage-clamp recordings performed n the whble-cell configuration ih non-spherical structures (Schaefer et al. 2003). The rational was that the whole-cell configuration is less damang to. the plasma membrane than tile extraction of a nucleated patch and will allow a more accurate estimation of the conductance density once space-clamp distortions were corrected for. Usixig this technique we re-examined the conductance density of voltage-gated po.tassium channels in l.ayer 5 pyramidal neurons. We show that the conductance den.sity i. higher than the one reported previously from nucleated patches. We use the new recording mode to investigate the postnatal development voltage-gated potassium channels at the soma. We also show that as previously reported the density of voltage-gated potassium channels decreases along the apical-dendrite of L5 pyramidal neurons. '_Dept. of P_ syc_c_hology, Tel Aviv University; The L-E-G Institute for Functional Brain Imaging, Tel Aviv Medical Center and Tel Aviv University School of Computer Sciences, Tel Aviv University; 'Dept. of Radiology, Tel Avtv SouraskyMedical Center; Diffusion tensor imaging (DTI) can be used for 3D visualization of specifi-e fiber bundles, and to indicate the involvement of white matter in vicinity of brain lesions.
Diffusion tensor imaging based fiber tractography necessitates definition of a seed region of interest (ROD that is located at the path of the investigated fiber network system. Based on [mown anatomical location a large number of fiber bundles systems could be identified on healthy subjects with high accuracy. Mapping of welldefined functional systems (motor, vsual, Iangt]_age) using fMRI is routinely done today for pre-surgical mapping. Nevertheless, brfiin lesions, especially space occupying lesions (SOL) often involve the white matter and altr the known anatomical path on which the fibers pass. Indeed, white matter deviation is a common consequence of SOL.
Nonetheless in many of these cases only partial or no functional deficit is observed leading to the assumption that the fibers are still partially intact and therefoie take a different route. In such eases, white matter mapping using seed ROI based on known, normal, anatomical location might be misleading. In this work we used fM.R:I, driven seed ROI choosing procedure in patients with space occupying lesions where probable dewation of white matter tracts hax/e been observed. The fMRI data was co-registered with the DTI to provide a 3D data set of both white matter connectivity and task related functional activity superimposed on high-resolution anatomical data set. From the fMR/activated areas we followed on white matter tracts using DTI to map the task related white matter tract. We used-mainly the motor and language related fMRI tasks mad concentrated ".m trackingthe pffamidal track (to connect the motor related network) and the suPerior longitudinal fascicules (to connect the language related network). This methodology opens a window-for assessment of brain connectivity in diseased patients. Israel Perturbations in the integrity of the blood-brain barrier have been reported in both humans and animals under numerous pathological conditions. The blood-brain barrier prevents the penetration of many blood constituents into the brain extracellular space, but it is not known whether perturbations ofthe barrier can affect brain function and consequently have a role in the path0genesis of cortical diseases. In this study we estabhshed a model for focal sruption o.f the blo0d-brain barrier "_m the rat cortex by direct applic_a,tion of bile salts. Importantly, direct neurotoxte ettects of the bile salts were excluded by unaltered intra-and extracellular recordings in vitro.
However, exposure of the cerebral cortex in vivo to bile salts resultedin a prolonged opening of the blood-brain barrier with subsequent long-lasfin.g extravasation of serum albumin to the brain extracellular space. This was associated with a prominent activation of astrocytes with no inflammatory response or marked cell loss. Using electrophysiological recordings in brain slices we found that a focus of epileptiform dscharges developed within 4-7 d after treatment and could be recorded up to 49 d postoperatively in >60% of slices from treated fiaimals but only rarely (I0%) in sham-0perated controls. Epileptiform actwity revolved both glutamatergic and GABAergic neurotransmission. It was also induced by direct cortical 53 application of native serum, denatured serum, or an albumin-containing solution. In contrast, perfusion with serum-adapted electrolyte solution did not induce abnormal activity, thereby suggesting that the exposure of the serumdevoid brain envii'onment to serum proteins underlies epileptogenesis in the blood-brain barrier-disrupted cortex. Although many neur0pathologies entail a compromised blood-tirain ba/er, this is the first direct evidence that it marc have a role in the pathogenesis of focal cortical epilepsy, a common neurological disease.  (24 GA) 1.5 mm above the anterior or posterior VTA to allow intracranial administxation of the non-NMDA antagonist, CNQX (1 nmol, 0.5/'YI per side), in order to fmd its impact on the rewarding effect of morphine in the Conditioning Place Preference (CPP) paradigm (unbiased procedure), and the induction of morphine sensitization in the same apparatus. Result: Regional administration of CNQX into t-lie anterior VTA blocked the rewarding but not the development of sensitization to the Iocomotor stimulating effect of morphine. However the_ effect of morphig,e on locomotion was attenuated by CNQX injected into the anterior VTA. Regional administration of CNQX into the posterior VTA had different impact on the rewarding and stimulating effects of morphine which has still to be analyzed. Conclusion: Our data suggests a critical role for non-NMDA receptors in the TA in opioid reward and dissociation between the rewarding and psychomotor sensitization effects of morphine. Given their flexibility and kinematic redundancy, the control of the octopus arm movements is computatonally quite complex. In previous studies a stereotypic reaching movement was discovered which reduces the complexi_ty 6f motor control. Study of out of water (OOW) reaching movements showed that during these movements the bend point does not travel within a single plane, probably due to the lack of enough muscle forces. Almost all OOW reaching movements were directed in a perpendicular direction to the water surface, and indicated constant attempts by the octopus of keeping the proximal part in that arm orientation. Although no evidence was Found that octopuses use correction strategies in the course of reaching movements in the water, such corrections were observed during the OOW reaching movements. Loss of steadiness was characterized by the fall of the proximal part of the arm towards the water and this was corrected towards having a perpendicular orientation during the movement. The kinematic analysis of these movements suggests that two distinct, independent mechanisms are operating during these reaching movements. The first one takes part in propagating the bend along the arm towards the distal part, andis probably carried out by the PNS (peripheral nerve system) of the .arm, as was found previously for reaching movements in the water. The second mechhnism controls the orientation of the proximal part of the arm, and is probably carried out by the CNS. The second mechanism is active during the whole reaching movement and is probably based on proprioceptive information.
Supported by DARPA and ISFgrants.
Chronic dietary lithium supplementation attenuates markers of aging in the hippocampus of C57BL mice Shaldubina A.', Shoham S. , Woodgett JR?, Bersudsky y.1, Belmaker RH.1, Agam G.' 'Ben-Gurion University, Beer-Sheva, Israel; 'Herzog Hospital, Jerusalem, Israel; 3Princess Margaret Hospital, Toronto, Canada; Lithium (Li) attenuates apoptosis and glutamate-induc.ed calcium influx and increases brain derived neurotrophic factor level. Since these actions oppose mechanisms of aging in the hippocampus, the present study examined the effect of chronic diet_ary lithium supplementation on markers of aging in the hippocampus of adult C57BL mice. Clusters of grains were detected by antibodies to inducible heat .hoek protein 70 and to glucose-regulated protein 78, and astro.eytic activation (increased astroeyte size) was detected by anti-glial fibrillary acidic protein. Chronic dietary Li supplementation reduced the number of clusters of grains b 70% and reduced astroeyte size in hippocampalCA1-2 field by 25-30% without affecting the dentate gyrus. The reduction in markers of aging was not secondary to calorie restriction since Li supplementation did not change body weight. Since Li inhibits glycogen synthase kinase (GS.K)-3betafz and since GSK-3tieta promotes apoptosis, e present study also examines the effect of ldaockout reduction in GSK-3beta level on the markers of aging. S_urprisingly, knockout reduction of GSK-3beta increased the number of clusters of grains by 2-4 folds and increased astrocyte size in hippocampal CA1-2 field by 25-30% without affecting the dentate gyrus. Thus, life long reduction in GSK-3beta level may result in acceleration of some aging processes. This sturdy warrants further examination of the conditions under which dietary_ Li supplementation to adults can prevent aging-associated cognitive decline.
Biological Psychiatry Laboratory, Hadassah-Hebrew University Medical Center, Jerusalem; Selective serotonin reuptake inhibitors are the most prescribed antidepressants for treatin d_epression. One problem of SSRIs is a 2-3 weeks delw ,of response atter onset of administration. Previous studie showed that acute administration of the SSRI fluoxetine to rats increases Vunaptic 5-HT levels, and long-term administration of oxetine desensitizes 5-HT 1A and 5-HT 1B autoreceptors. This effect may play a role in the delayed response to treatment in humans. Mood disorders are more frequent in women. It was also suggested that there are gender differences in the response to antidepressants. Yet, most of the animal researches are done with male rats. In this work we asked whether 5-HT autoreceptor response to fluoxetine administration is differ between male and female rats. We treated Sabra male and female rats, and Sprague-Dawley female rats, with fluoxetine (10 mg/kg, 7 or "12 days). 5-HT levels 5-HT1A and 5-HT1B autoreceptor activity_ were meased by in vivo microdialysis and analyzed by HPLC.
We found that both 5-HT1A and 5-HT1B autoreceptor activity as measured in the cortex, were reduced in Sabra male r/ts after 7-day administration of fluoxetine (10 mg/kg). However, the same treatment, as well as a 14-day treatment with fluoxetine (10 mg/kg), had no effect on :-HT autoreceptors activity in the Sabra female rat. Early research found that 7 and 14 days administration of fluoxetine (10 mg/kg) desensitized 5-HT 1A autoreceptor in the cortex of Sprague-Dawley male rat. In this study we found the same effect in Sprague-Dawley female rats, as well as desensitization of cortical 5-HT 1B autoreceptor. We 54 conclude that the gender differences in 5-HT1A and 5-HT1B autoreceptor response to sub-chronic fluoxetine administration are stram related. Whereas sub-chronic fluoxetine has the same effect on 5-HT aoutorectors in males and females in the Sprague-Dawley strairi, 5-HT autoreceptors response to fluoxetme differs between male and female in the Sabra strain. However, this hypothesis has been challenged by findings that some patients with PFC damage can pass ToM tasls. Based on our previous f'mdings, t is suggested that the behavioral deficit of individuals with PFC damage may be due to an impaired 'affective ToM' and diffictilty at the level of integration between the cognitive and the affective facets of ToM, rather than to a general impairment in ToM. To test this hypothesis we designed a novel computerized task that assesses the ability to judge first and second order affective vs. cognitive mental state attribution, based on eye gaze. The perftrmance of patients with localized lesions in the PFC (n=23) was compared to responses of patients with posterior lesions (n=12-) and healthy control subjects (n=46). Whereas, healthy controls and patients with posterior lesions made less errors on affective as compared to cognitive onditions the frontal patients showed the opposite trend. In additaon, patients wth PFC lesions made stgnificantly more errors and we.r.e significantly slowe.r to respond in the affective conditions, as compared to controls. Furthermore, both right and left PFC lesons were associated with a selective impairment in both first and second order affective ToM whereas they were not impaired in cognitive ToM tasks. T13.e puroose of the. present s.tud.y was .to. assess .th.e relafitnsfiip between brain metabolism and the empathic. re.sponse. Six fight-handed healthy volunteers were scanned with oositron emission tom. ography (PET) and [F-18] fl.uoroteoxyg!oucose twice; dunng an interactive inttrview about neutrgl story themes an during an interactive interview about an emoathic response-eliciting stqry. Objectives: Serotonin (.5-hvdro.xytryp.tamine 5-HT) is a neurotransmitter syntheszedin the ra.phe nuclei Qf the brain. stem in the CNS and also in the periphery..Dysfunction 9tthe serotonergic system has been implicated in .the oathogenesis of psychiatric, disorders. Try.ptolhan hydrovlase (TPH) s the rate limiting enzy.me n 5-HT bosy.n...thesis. For more than a decade only_ one gene enctding TPH was identified in vertebrates, l, tecently, a 55 TPH gene designated TPH2 was detected and ocated on human hromosome 12, a usceotibility region for affective disorders. TPH2 is predominantly expressed in the brain, while the classical TPH gene, TPHI, is expressed in leriplieral tissues. The discovery of the brain-aBundant TPH2 gene iustilies a new conceot of the CNS serotonergie system. TPH2 rather than TPH1, has now become a candidate ge'e for 5-HT-related affective disorders. Metho.ds: We compared TPH2 mRNA levels in postmortem parietal cortex of unipolar-d.epre.ssion, bpolar and schizoohrenia p.atients vs. control subjects and using realtime RT-PCR. Results: No signi3canf difference in-TPH2 mRNA levels was found among the four diagnostic groups. Conclusions: The lack of difft"rence may suggest that this gene. is not involved in the etio.log, of elifier of these psy.chi.atrie disorders. Alternatively, it may be that the pai'ietal cortex is not the relevant brain area mvolved in the pathophysiology of these disorders, or that p.osttranscriptinal modifi.eations of TPH2 mRNA occur in these patients, causing claanges in protein levels and/or enzymatic activity. lifferences in calbindin levels between Fymphoces and brain may be reslLo..nsible for our orewous finding of_ reduced IMPase activi_ty in lymp.hoces but not brain or b.ipol patients, and whether cailbindin protein levels are altered in postmortem brain from bioblar patients vs.
control subjects and schizophrenic .and" major depressive patients. Methods: IMPase activity in human postmortem brain, specimens with or without 10 -M human To examine the role of inflammatory cytokines and choliner#c signaling in mediating the effects of stress on mood and memory, 33 generally healthy volunteers were administered a comprehensive neuropsyehological test batte before and after a moderate surgical procedure.
Each subject was tested on three occasions: Several days before surge (baseline), on the morning of the surgery day (i.e., psythological stress), and one dy after surgery. Acetylcholinesterase (ACHE) activity, and the levels of interleukin (IL)-I, IL-lra, IL-6 and cortisol in the serum were measured in each session. 18 control subjects went through the same procedure. A.t baseline, lower levels o.f AChE activity were significantly associated with elevated 56 anxiety levels. Anxiety and depressed mood were significantly increased before and aer .surg_ery. Surgeryinduced m6od alterations were associated wth changes m AChE activity: Patients who demonstrated stress-induced reduction in AChE activity showed a marked elevation in anxiety and depressed mood, whereas patients who demonstrated elevation in AChE activity displayed almost no mood alterations. Both on the surg_cry day, and on the day after surgery, there was a marked decline in memory. Following surgery, the levels of IL-6 were significantly increaseff, and were significantly correlated wifh smaller impaimaents in word list and complex figtv_e delayed recal!.
Polymorphism in IL-lbeta was si_gnificantly associated with IL-6 elevation following surgery (i.e., the surg.ery-induced .increase in IL-6 levels was .fwice as hig h in allele homozygous patients compared to patients with allele 2). In addition, memory impairment in the allele homozygous patients was smaller compared to the other group. Thus, while cholinergic sig_aling is associated wth s_urge.ry.induced mood mo&fications, IL-6 is associated with protection from surgery-induced cognitive disturbances, which va_ry according to genetic predisposition in stressinduced II5-6 production. Rat brain synaptosomes contain a functional thrombin receptor PAR-L Shavit E_G., Aronovich R., Rehavi M., Chapman J. Dept. Physiology & Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, lsrael.; Background: Thrombin is a key factor in coagulation and is considered to have a role n seizure production. Thrombin mediates many of its ettects through specific protease activated receptors (PARs). The discovery of PARs in the nervous system has led to new insight regarding the potential physiological functions of thrombin. Objectives: To examme PAR-1 agonist peptides pharmacological effects on synaptosomes which may contribute to seizures. Methods: Crude synaptosomes were prepared from rat brains by centrifugation. The levels of phosphorylated ERK-1/2 induced by thrombin and PAR-1 agonist peptides were measured using western blot. Results: We observed a 2-3 fold increase in the level of ERK-1/2 phosphorylation in response to thrombin and PAR-t agonist peptides relative to control non stimulated synaptosomes. A 2 peaked dose response curve was obtain ed with maximal responses at 30 microM and 10 nanoM. Conclusions: The results indicate that rat brain synaptosomes contain functional PAR-1. The physiological effects of the signal transduction pathways activated by this receptor remain to be evaluated. Overactivation of NMDA receptors is involved in neuronal cell death that occurs followiiag brain ischemia. Calcium influx through NMDA receptors requires the binding of both glutamate and a coagomst, glycme or D-serine. Since both glycine and D-serine occur in the brain, the relative roles ofeach NMDA receptor coagonist is not known. To examine whether endogenous D-serine plays a role in neuronal death resultm/g from excitotoxic insults in the hippocampus, we used rat brain organotypic slice culture as a model. HPLC analysis revealedsignifieant synthesis of D-serine by cultured hippocampal slices, ranging from 6 to 12 micromolar in the culture medium. Robust cell death was observed by addition of either NMDA (0.5 mM) or kainate (0.1 mM) as determined by pr0pidium iodide uptake. Application of recombinant D-serine dehydratase (DSDA), an enzyme that specifically degrades D-serine, depleted D-serine levels ,in the culture medium and slices.
This was associated to a drastic inhibition of neuronal death elicited by_ NMDA, but not by kainate. The neuroprotective effect of DSDA was fully reversed by addition of excess glycine or D-serine, indicating that the effect of DSDA was not due to a nonspecific inhibition of NMDA receptor activity. The present results indicate that endogenous Dserine is essent!al .for neuronal injury involvirig NMDA receptor overactvatton. Ras dependent ErbB4 signaling, possible mechanism of regulation. Shliom N._, Erlich S., Kloog Y., Pinkas-Kramarski R. Dept, of Neurobiochemistry. Tel-Aviv University, Ramat-Aviv, 69978, lsrael; The ErbB subfamily of receptor .tyrosine kinases consists of four receptors. ErbB4 receptor is highly expressed in the nerve system and its higli affinity ligand is neuregulin r (NRG). NRG recogmtaon event activates the recepto s intrinsic tyosine kinase activity and initiates a network of signalin.g pathways regulating cellular proliferation, survival, chemotaxis, or differentiation. Among the cascades activated by ErbB4 is the prominent Rasdependent signaling pathway. Our previous studies have shown that NRG inauces neui'ite outgrowfl and protects the PC12-ErbB4 cells from death caused by various apoptotic stimuli. Furthermore it was shown that activated Ras can activate ErbB4 receptor in a ligand independent manner. This activation depends on multiple Ras effector pathways in an autocrine independent manner. In the present study we demonstrate that the Ras inhibitor FTS, inhibits the NRG-mediated PC 12-ErbB4 rescue from serum deprivation treatment. In addition the expression of dominant-negative Ras in these cells prevents cell differentiation. In order to examine whether the phosphorylation of ErbB4 by activated Ras is due to the tosine kinase activity of the receptor itself or due to flae activity of an unknown cyt.9plasmtic factor, we have constructed an ErbB4 receptor witla a point mutation in the ATP binding site. Preliminary. results have shown that this receptor, transiently expressed in BOSC cells, does not bind gamaATP and tlierefore abolishes the intrinsic tyyosine ldnase activity. Based on these results we suggest fhat Ras signaling pathways on one 57 hand, lead to cell differentiation and viability, and on the other hand involved in a positive feedback signal to activate the ErbB4 receptor. Our future plans are to stably express this mutant receptor in PC12 cells in order to better understand the mechanism of Ras mediated ErbB4 activation.
Double dissociation between the ventral and dorsal streams during object and action recognition Shmuelof .L.', Zohary E. 'Neurobiology Dq_pt., Hebrew univers#y; 21nterdisciplinary center for neural computation; Neur_opsychological case studies indicate the existence of two ft/nctionally separate visual streams, but due to the few cases, this distinction remains controversial. Using fMRI .in humans, we provide here evidence for the dissociation between observed action and object recognition. In ex_pefiment 1, subjects viewed movie clips of the fight h.a0.d, on the right visual field, reaching and grasping objects placed on the left side of the screen. A mirror irfiage ofthose movies (left hand grasping objects on the fight side of the screen) was also sh6wn. Contrasting th fMRI activation in the two conditions, we find that in dorsal areas (i.e. anterior intra-parietal sulcus: alPS) the dominantly contralateral hemispheric activation is determined by the hand location while in ventral areas, (i.e. fusiform gyms) the a.c, tivation is in the hemisphere contraletral to the object s position. Next, subjects watched clips showing ten different (or identical) hand manipulations of various (or the same) objects. Using a two-tactor ANOVA, we measured the adaptation effects of repeated viewing of objeg_t manipulation and/or object identity. Voxels showing signiticant fMRI adaptation during tlae observation of same grasping compared with different gra.sp'.mg move.ments of diff&ent objects, were mainly found in the parietal cortex, (i.e. alPS and postcentral sulcus). On the other hand, voxels showing significant adaptation during the repeated observation of the same object, compared to different objects were found in the occipito-temporal cortex. Thus, we show a double dissociation of function between the two path_ways. These results are congruent with the "direct ma_tchifig hypothesis", that suggests that action recognition is based on mapping external actions to our own motor system and extefid th classic division of labor between the vental and dorsal visual streams, suggesting that the dorsal stream may also be involved in the recognition or actions made by others.  (Rombouts et al. 1996). Detection of an element that differs significantly in a single dimension is an easy task, with perf6rmance that is independent of the number of distractors (Treisman & Gelade, 1980). We looked for effects of eye dominance on visual search. 13 subjects participated in the experiment; each had similar visual achities m their two eyes, and normal or correctedto-normal vision. Dominant eye was determined using the Hole-in-the-Card test (Durand & Gould, 1910). Using redgreen glasses, subjects viewed a briefly presented 8x8 array of een and red hnes oriented at 60 degrees, followed by a masking stimulus after a variable stimulus-to-mask onset aachrbny. On half of the trials, one element was replaced by a red or green line oriented at 40 degrees, with the 8 lines surrounding this target having the same color as the target, the opposite color, or a mixture of the two colors.
We tested for differences in performance when subjects used the dominant vs. the non-dominant eye., and checked if any difference depends on the eye viewing surrounding elements. We found significantly better perf6rmance when the target was seen by the dominant _eye, especiall when surrounding elements were seen by the opposite e)e. We conclude that the dominant eye has visual processing prio.rity, perhaps arising from inhibition of non-dominant eye information.
Supported by an Israel Science Foundation "Center of Edellence" grant and the US-Israel Binational Science Foundation (BSF).
We hay e. fo.und, evidenc,e of o?dative/nitrative stress, detected by antibodies to nitrotyrosine in the septo-hippocamPal system as an early event after icy STZ injection. This was associated with damage to myelin and disruption of spatial learning. Activtty of protein kinase C (PKC) isoforms has been implicated in development and maintenance of myelin and in learning. The present study explored the effect 6f STZ on PKC beta 2 (PKCb-2). STZ 0.5 mg was injected bilaterally to male rats weighing 300-320g. Immunohistochemical staining of brains 7 days later revealed a 10-30% reduction ofPKCb-2 levels in cortex, hippocam_p.us, striatum, .corpus. callosum, and internal eapsulre. Deficits in episodic cl spatial memory were seen 15-60 days after iev STZ ifijeetion. In order to verify a contribution of oxidative stress to the memory deficts and enzyme changes,, rats were given daily se. rejections for 2 weeks of 0.2 6ag&g of rasagfline. Rasagiline has shown efficacy in patients with Park]nson's disease and to prevent cell death induced by oxidative nitrative stress in SH-SY5Y neuroblastoma cells. We found that rasagiline increased PKCb-2 immunoreactivity in all brain regions in which this was decreased by STZ, and completely restored it to control levels_in the hippoeampal CA1 pyramida layer. Rasagitine signi/lcantly reduced the spatial mem0r) dificits seen 60 days after two STZ injections. Our findings suppoR the hypothesis that the damage to myelin and memory deficits iridueed by icv-STZ irivolves a cascade initiated by oxidative stress and reduction in PKCb-2. Icv-STZ can serve as an in vivo model with which to screen potential neuroprotective agents for their ability to prevent myelin damage and memory impairment.
The financial assistance of Teva Ltd is gratefully acknowledged The involvement of 5-HT and octopamine in short-term plasticity in the octopus vertical lobe Shomrat T. , Feinstein N. , Klein M.', Hochner B. a__ pt. of NeurobJol_ogy,_ lnsatute of Lfe_ Sciences; Hebrew University, Jerusalem Israel; "-_DePt. bf Physiological Science, UCLA; Los Angeles, CA; Octopuses are unique invertebrate mollusks with a highly developed centralized brain and learning ab!lities comparable to those of vertebrates. In a previous study we. discovered a hippocampal-like LTP in the octopus vertical lobe (VL), an area of the octopus brain involved in learning and memory. To find out whether the well kaaown mechanisms of molluscan synaptic plasticity are conserved in the octopus VL, we first looked for the presence of 5HT in the VL complex. Fibers immunopositive for 5HT were found in the V[, complex and stained terminals were found mostly in the VL neuropil. This finding led us to reinvestigate the involvement of 5HT in-VL synaptic plasticity. In contrast to our_ previous work, where we tested only 5HT concentrations effective in Ap_lysia (10-50M), a 2-6 fold facilitation of the synaptic fieldpotential was induced when higher concentrations (100-2001aM) of 5HT were used. In contrast to the activity-dependent potentiation, the effect of 5HT was readily reversible upon washout and was not occluded by induction of LTP.
Octopamine had a similar and synergistic effect. The_ phosphodiesterase inhibitor IBMX facilitated the effect, ot 5HT suggesting the involvement of cyclic nucleotides. Paired-p[se fiieilitation was altered by 5HT and by octopamine, suggesting that these substances act presynaptically. The effects of 5HT on the biophysical properties of dentified presynaptic and postsynapidc cells of the VL were studied in whole-cell current clamp in enz3'matically dissociated neurons.
Prelimin..ary experiments showed an increase in membrane excitability which resembles, at least in par[., the 5HT-indueed modification of these properties m Aplysia sensory neurons. Taken together, these results s.uggest that 5HTdependent short-term neuronal plasticl.ty, which is associated with simple forms of learning in mollusks, is conserved in brain areas of the octopus that mediate complex forms of learning and memory. Supported by BSF.
Isolating the role of visual perception in dyslexia Shovman M. , Ahissar M.
Dept. of Cognitive Science, Hebrew University; 2Dept. of Psychology, Hebrew University; Israeli Center for Neural Computation; Despite the current prevalence of phonological theory of .dyslexia, ther.e are s.ey,eral theories (e.g. the magr_ocellular .h!fpothesis) that attribute a key role to visual deficits as a basis for dyslexia. They stem from dvslexies' introspective reports of visual discomfort while reading ,and are supported by findings of various visual deficits in dyslexic.
largely explained as resulting from impaired perceptual memory rather than poor immediate perc.eption. To assess the role of .(possibly impaired) visual perceptio..n in dyslexics' reading, we composed a task at was smail to normal reading n its visual features, but lacked other aspects of reading (phonological, mo.hological, semanti.c etc.) and compar&l performance of ds.lexics and.conSols 9 n 1 under several oaradigrns. The t.ask was. to iden..tity a letter of an alphabd unkriown to subiects, but similar to Hebrew and English in all graphical details (11 simil.ar Georgian letters)? Eight different_conditions were assessed, meas/aring threshold-duration or-p.re_sentation (SPA) and threshold contrast levels for identilication of small and large letters, with and without flanker letters, with and without white noise. Twenty adult native-Hebrew speaking dyslexics, mainly students, and 20 controls, matched .fo gender, age, and general coggitive abiliti.es, Earticipated in this stud[. We found all the predicted ellects in both groups. Namely, adding flartkers and decreasingletter size ncreased. threshold SPAs, and adding w-hite noise increased contrast thresholds. However, there was no difference between the experiment group and the controls, neither in single-set comparison, nor in effect magnitude, nor in an all-inclusive analysis of variance (MA-NOVA d=0; p>0.9). We conclude that the visual processing deficits found among dyslexic individuals by other researchers do not affect reading performance, and at therefore, the cause of their reading deficit resides elsewhere.
Mechanism and circuitry for coarse and fine discrimination in the insect olfactory system Sivan E.. Kopell N.
-jgor BioDynamics, Boston University; We propose a solution to a major challenge in the study of olfaction, differences in coding between fine and coarse discrimination of odors. W.e hypothes-ize the existence of. a hard-wired circui.try in the insect brain connecting .tOe antenna lobe (AL) the mushroom body (MB) anl the lateral horn (LH)" constructed of repetitive ud non-9verlapping substructures that gove.m the connections between ffiese reions. Using the above circuitry, we propose two parallel mechanisms, on_e f9 r odor .clusteri.ng and" one for fine discrimination. In line with results suggesting that the KCs are coincident detectors, fine discrimination is encoded by the activity of the Kenyon cells (KCs) in the MB. Our mechanism for coarse discrimination is new, and uses a population code of grgups of inhibitory neurons in the LH. We show that these mechanisms can explain the expemnental results that AL qscillations are required for f'me but not for coarse discrimination. Qur theory also fits the data showing that non-associative discrimimition can still be performed when the MB is completely removed. In addition, it sheds light on physiological results recording the activity ofthe var.'ous n.eurons when an odor. is presented" for examlale, it predie.ts that odors that strongly activate e AL will'also -.sFongly activate the LH neurons, while the KCs fire .sparsely. Odr_ hypothesized circuitry also .sheds light, on rest.s o1: mao.y exqgeriments that map the connectivity between these regions.
Cortical plasticity in the visual cortex of the bilingual blind: an fMRI Study Spiegler R.H:., Zohary E. Neuobiology Dept., Hebrew University, Jerusalem, Israel; Recent studies, using imaging (fMRI) or transcarnial magnetic stimulation (TMS) tecffniclues in humarts, indicate. that" the visual cortex of the blind is recruited for other se.nsory functions as well as language 13rocessing. Is .t.'s plasticity restricted by c.ritica.1 peri?ad?" Whi.le s,f eti ns question has been tackted us.ng .a compan_so.n qetw.e early bl.ind.vs, late blind, we took advantage o.I the lact that our polyglot subjects acquired their two langgages at different ages. Using fMRI, we examined 9 bi.l'm.gual con.genitall blind sub-ieets whose mother tongue_ is ttebrew ..and le.arned, English, later in life (-age I0). _Tge s.ubjeets listened to chimera' nouns (a superoosition or a Hebrew noun and an English noun, recpr.decq one on top of.the other). During one condition subjects were instructed, to repeat the noun heard (i.e. "repeat'), while during the other, theywere asked to generate a verb to the heard"noun (i.e. "verb generation, VG'). This procedure was carried out in each language 0.e. Hebrew & English) __m_a block design fashion, accorling to heard instrufftions: Wh..e. contr.as .t[g activation elicited-during VG and repeat conditions, similar left lateralized activation was foufrd for both languag throughout the whole brain including the visual cortex. ISeft lateraization was also observed in classical lan.g!ba.ge areas (IF.S p.recentral sulcus) in congruence with fuKiings from sighle/l subjects_ performi.ng the same .task. H__oweve(., there was no sgniticant di.ffeience in the fMgl activation generated y the two language.s, in any cqrtical region, ncludin the visual cortex. This suggests .that. either. @e se.cond Fangg.age was acquired within the eritica period tor plasticity. (which is thus longer th 10 yr.s) or alternat'ely, regions in the visual cortex orthe blihd hight be engaged in semantic processing at an abstract level (regar/iless of the language of the hed words).
Effects of bilateral electric stimulation of the insular cortex on conditioned taste aversion in rats Stehber J., Levy D., Zangen A., Dudai Y.

Jeptl Of Nurobiology, Weizmann Institute, Rehovot
Newly acquired memories can be disrupted by agents such as protein sy..thesis inhibitors, during a maturation pefi.od called consolidation. Ample evidence now indicates that mature memories can also be disrupted by the same agents immediately after memory reactivation, in a proc_ess dubbed reconsolidz/iion. We set out to find parameters tor transient targeted brain stimulation that could lead to te.mpora dysfunction of brain substrates during acquisition, consolidation and reconsolidation of memory. Toward that end, we used conditioned taste aversion (CTA), a tastemalaise association, which is known to be subserved by the insular cortex, which contains the taste cortex in the rat.
Our. preli.minary resu.lts .sho.w. that ,acq.uisitipn lf conditioned taste aversion {,CIA) can oe msruptea y. bilateral electrical stimulation. (30 min..high frequency) of the insular cortex, but not when stimulation is berfoi'med dorsal or lateral to the insular cortex. The stimulation was preformed from the presentation of the conditioned stimulus (taste) untill 0 inin prior to the presentation 9.f...tl. unconditioned stimulus (malaise ind.ucmg agent, These results suggest that electrical stimulation oI-a localized brain region could be used as a tool to disrupt memo.ry processes such as enco..dng, co_nso.lid.ation, and possibly post rea.etivation recon.soli.dato.n. In the latter case, Dep. -of Clinl iochem., Sackler School of Medicine, Tel-Aviv Univ. Tel-Aviv 69978, Israel.; Activi.ty-dependent neuropyotective protein (ADNP) is. a recently discovered homeobo profile containing gene that is essential for brain formatitn (Dev Brain Rts. 2003 144:83-90). Previous studies demonstrated an active site of the protein that included an eight amino acid peptide NAISVIPQ (NAP) that show.ed a wide range of neuroprotective activity in vivo and in vitro (J Neurochem. 1999(J Neurochem. 72:1283. In the present study, we examined the neur13otective properties of ADNP. The Human AI)NP eDNA (J Bio.l Chem. 2001, 276:708-14) was sub-clon.ed into a vector that contains VP22, a He.rpes us p.rotein that allows penetration of fised_proteins through cellular membranes. The recombinant fusion protein VP2.2-ADNP, was expressed in E. Coli purified and assayed in diffcrentmted pheochromo',oma (PC12) cells. VP22-ADNP was detected within the cells after 25-min incubation by. western blot hybridization. However_using i.mmuno.cytochemis.try, only minute amounts of ANDP were detected mtra-cellularly after a 25 min. incubation period.
Pre-incu.bation with VP22-.ADNP protected PC12 cells aga'.mst beta amyloid lptide toxicit as well as from oxidative stress. VP22 b itself was devoid of protective activity. To examine if YP22-ADNP prptects against an apoptotic-like mechanism, alterations hi the amount of the lro-apoptotic protein P53 were measured in PC I2 cells.. lesults showed that p53 increased by 3.5 fold from control levels in the presence of H202 while treatment with VP22-ADNP prior to H202 Xl3OS significantly reduced the p53 pro[ein lev.el. Thus, ADNP inhilited stress-induced p53 expression indicating protection a.gainst ap?p.tosis. Taken together, these studies suggest that recombinant AD.NP lrovides cellular p_rptection against various toxic insults.
5upp.orted by ISF, BSF the .Lil and Avraham Gildor Chair for lnvestigation oJ (rowt/ lactors, Allon Therapeut'cs and the Institute Jor the Study of Agin Z. PKC isoforms pla: selective roles in the migration, and intrinsic signaling molecules. In [his study we e_xplored the role of p.ro.t.e_i_n [inase C (PKC)in the proliferation, migration and ditterentiation of MNPC. PKC a fa.ml." y of phospholipid-dependent kinases is highly exo'essed in the. CNS and plays i.mportant roles in ihe iro'liferatiqn a-nd differentiation of glial and neuronal cells. We found that.the neurospheres exoressed PKCalpha, beta2 delta epsilon, zeta and mu and their differentmtion was c_comiamed by. increased expression of PKCbeta2 and PKCze.t]n lnantl by a restricted expression of PKCgamrqa fnin the neuronal cells. We observed a slower electrophoretic mobility ot-PKCalpha and PKCepsilon and an increased phospliolation of PKCeosilon on serine 729.The PKQ activator PMA _specifically increased the generation of astr.ocytes. To fui'ther explore the role of specific PKC isoforms in the differentiation of the MNPC, we employed adenovirus vectors expressing PKCfnisof0rms and their respective kinase ead-mutants. We found that overexpression of PKCgamma selectively increased the generation and mi_'gr_aton, of.neurons. In con.trot, overexpression of l'lSepsilon selectively, increased the proliferation of GFAP+ cells whereas the KD mutant increased the generation of oli'godendroces. Mutation of serine 729 on PKCeosilon to alanine abolished the its proliferative effect. PKCalpha and PKCdelta did not play a_ igniticant role in the roliferation or differentiation ot-MNPC however the PKCalpha KD mutant abolished the effe.c.t f PMA 'n migration of GFAP+ cells. Our results imp.licate PKC as a major signaling pathway,in the function of. MNPC and suggest that different PKU isoforms c.an selectively .direct e fate of MNPC and affect_the generation or-neurons astrocytes and oligodendrocytes om ese cells. While the occipital cortex of the congenitally blind .can be activated by tactile stimuli .(as well as auditory, ones), most of the evidence indicates that this activation is associated with verbal tasks, such as verb generation and Brai!le reading. Furthermore, tactile relaed activation in the occipital cortex can be found in. blindfolded sighWxl s.ubjects, .a.er 5 dys. This suggests tgat .Braille, connecting phonics with tactile sensations, may be the critical link fo the recruitment of the visual cortex, to take part in language processes. This study re-examines the emphasis on language, while demonstrating a larger effect of mnemonic properties of the task, eecially m the primary visual cortex. We compared verbb.1 and musical mnemome tasks, as well as verbal and musical perceptual tasks. The nmemonie tasks included the recognition of previously learned words and tunes, and the perceptual tasks were th.e detection of a repeated tone or letter. We found that the mnemonic tasks generate robust activation in the visual cortex of blind compared with the perceptual tasks. Higher activation in V of the blind, in both hemispheres, was found during the musical mnemonic condition than d..urin the verbal task. This preference may be partially attritutea to the depth and length of the encoding process Of the lists, to-be-remembered, nto long-term memory, which was greater during the musical condition. Hemispheric differences in activation pattern were found in the lateral ventral occipital_regipns. Thus, the left lateral occipital cortex was significantly more activated than the right one, during the verbal perceptual (phonological) task. This hemispheric difference is compatible with the asymmetry observed in the conventional langlaage regions, grossly maintaining a lingual dominance in the]eft hemisphere and a musical dominance in the right hemisphere.  Electrical activity in the brain shows organization at multiple time and spatial scales. Here we studied the correlation between well-separated units, clusters of units, and local field potentials (LFP) recorded from 2-4 ele..ctrodes simultaneously during on-gping aetivi in auditory cortex of halotliane-anesthetized eats. We show that the loea.1 neural tissue has a sigr_ifieant degree of burst activity and temporal correlation. The numb of spikes fired .by single units during 200 ms riods with no stimulaf,ion was found to be correlated with the responses of other units recorded from the same and from nearby electrodes. Moreover, LFP recorded from those electrodes was significantly correlated with the number of spikes recorded at the same time period. These results support the hypothesis that the reetrded spikes are only a few representatives of a temporally coherent on-goin activity in the .neural tissue. These findings imply that LFP, which is much easier to record than well-separated spikes, can have substantial amount of informatton abotit sensory stimuli and is therefore a good candidate for decoding the neural activity, as it can replace spike sort'mg in some eases. For example, stimulus-specific adaptation, which was previously demonstrated hi A1 at the single neuron level by .analysis of the spike counts in response to standards ag.d deviants in an oddball paradigm, is shown here to be present in the LFP reeord&l by the same electrodes as well. formation, unaeco.mpanied, by ehanes in bone r.esoon, was observed in the distal I-emoralmetaphysis 1-8da.. post CHI. Periosteal bone formation in the mid-diaphy_is was initially enhanced and then declined with time alter CHI. The CHI-induced increase in bone formation was in.dependent of the mouse strain and gender. We.then use, mice deficient of the neuronal, edomin.antly ee.ntral cannabinoid recep.t (CB1) to eXllore the bone-to-brain l.athways involv&l in the CHI-induced increase in bone IOrmation. These mice have a basal low bone mass phenotype secondary t9 low bone formation and high bone resorplaon. The bole tbrmation rate of the CB loekout ice was unaffected .by CHI. Abnormally high Glutamate (Glu) levels in brain interstitial and cerebrospnal fluids are the hallmark of several neurodegenerative conditions that result from acute insults, such as stroke, traumatic brain inj.ury or meningitis. As a novel neuroprotective strategy, we have established that a decrease of deleterious Glu n brain fluids can be achieved by accelerating the naturally occurring brain-to-blood Glu efflux. This is produced by decreasing blood Glu levels upon intravenous (IV) administration of p,vruvate (Pyr), ahd/or oxaloacetate (OxAc). These compounds act as blood Glu scavengers since they activate respectively, together with their co-substrate Glu, the blood resident enzymes Glu-Pyr transaminase and Glu-OxAc transaminase with transform Glu into 2-ketoglutarate. We have investigated the acute neuroprotective effects of _Py-r and OxAc m rat models of closed head inj .uD' and of global isehemia. In the_ rat model of closed head iiajury, th IV administration Pyr and/or .OxAc performed hour after head trauma was f.tund to dramatically improve the neurological status determined after 48 hours. OxAc was superior to p while the neuroprotective effects of OxAc were abolish&l when the rats were treated with OxAc + Glu suggesting that the beneficial effects of OxAe are likely to be due to its blood Glu scavenging property. This suggestion is supported by the observation that rats treated wth IV Glu have a worse outcome than control rats. In the rat model of transient global ischemia, the 30 min long IV administration of Pyr mad OxAc, overlapping the 10 min long ischemia, was found after 7 days to cause the preservation of the vast madori of brain neurons in comparison to the death of 60 704 of neurons in control animals. We conclude that scavengers that reduce blood Glu levels cause brain neuroprotection by increasing the brain-to-blood Glu efflux decreasing thereby, the excit0toxic and deleterious effects of the high Glu levels in brain fluids.
The effect of magnetic field on olfactory processing Telles C.', Sobel N.
,Helen Wills Neuroscience Institute, UC Berkeley; 2Psychology Dept., UC Berkeley; Fun.ctional .magnetic resonance imaging is increasingly used as a tool to elucidate the neural substrates of olfaction.
However, it is possible that the magnetic field used in functional imaging may itself affect olfaction. It is known that the directibn and strength of a magnetic field have art effect on visual perception tasks. Likewise, the strong magnetic field of an MRI scanner can induce phantom gustatory perception. Anecdotal observations in our lab. oratory suggested that olfactory, intensity_perception w.as enhanced under a strong magnetic field. To address this possibility, the UniversiW of Pennsylvania Smell Identification Task (UPSIT) vas administered to 9 subjects both in the MRI scanner (4 Tesla Varian) and out of the magnetic field in a mock scanner. In addition to identification, subjects rated stimulus intensit'v and pleasantness on a visual analog scale. The .blood brain-barrier (BBB)protects the brain from circulating xenobiotic agents. Disruption of the BBB is known under many 13athblogical conditions. However, the pathophysiology-, time span, spatial pattern and consequences 6f BBB disruptions are unknowh. In animals, several invasive method have been developed to quantitatively measure BBB permeability. However, most 6f these methods are not applicable to humans. We have developed an image analyses program for quantifying BBB permeibility to. contrast agents inje.cted during routine brain tmages procedures-computerized tomograp-hy (CT) and magneti6 resonance imaging (MR1). By image analyses we were able to make a statistical comparison between brain images taken before and after the injection of the contrast material as well as measure % enhancement values. In a group of patients BBB disruption detected by CT or MRI, was verified by_ single photo tomogra_phy (SPECT) following the injection of 99mTcdiethylenetriaminepentaaeetic acid (Tc-DTPA) or by albumin concentrations in the cerebrospinaI fluid. BBB disruption was found to be either diffuse or focal, and in most cases (>90%, n= 101) was found to be confmed to the cerebral cortex. In some cases focal disruption of the BBB persisted over long periods of time (weeks-years). While various pathologies were found to present with changes in BBB permeability_, no single pathological process was found to underlie dis ruPtion m allpatients. Two sub-groups of. patients with focal, long-lasthig.BBB disruption were subjected to quantitative electroenceplialographic recordings. These ncluded 18 patients after mild head trauma and 12 patients post surg!cal removal of a benign meningioma. In both groups, _spatial correlation was found between areas of BBB disruption and slow-wave abnormal cortical activity. We conclude that BBB disruption is a common disorder in the diseased cerebral cortex, and when istent may be associated with abnormal cortical ion.
Effects of pleasant and unpleasant gustatory stimuli in anorexia nervosa as revealed by spectral and dimensional EEG changes. Dept. of Neurology, University School, Pcs, Hungary; Anorexia nervosa (AN) is considered a multifactordetermined disease, with biological and environmental factors contributing to its evolution. The 13athologically altered processing of gustatory stimuli could be an important factor in the development of AN. The aim of the present study was to investigate the effects of pleasant (chocolate) and unpleasant (bitter tea) gustatory stimuli on the EEG in both a healthycontrol group and in a group of AN patients by linear .(frequency spectralanalysis, Omega complexity) and nonhnear (PD2, characterizing dimensional complexity) EEG complexity analysis. The subjects were exposed for two minutes to pleasant (sweet chocolate) and unpleasant (bitter tea) gustatory stimuli. The EEG was record&l right after taste exPosure followed by mouthwash. The EEG was recorded by the NeuroScan system The EEG recorded b3--12 electrodes (Fp 1, Fp2, F3, 62 F4, C3, C4, T3, T4, T5, T6, P3, P4) was selected for further off-line analysis. In AN patients lower dimensional complexity_ and higher amount of relative theta power was obse..rv.ed than that seen in controls, independent of taste co.n.ditions. Higher Omega complexity was s_e_en in control subjects in theleft side iri'espectve ortaste ellicts. No such hemispheric difference was observed in AN. The tack of a significant Omega complexity change in response to exposure of sweet taste in the left side in AN pat.ents may correspq_nd to a decreased sensitivity to such stimuli in these subjects. Since all the patients who participated in the present S.tudy had episodes of abnormal wasting prior the investigation it seems reasonable to suppose tliat a longlasting effects of malnutrition could be manifested in low dimensional EEG and higher amount of relative theta (4-8 Hz) activity.
"Juvenile" stress as a risk factor for.impaired coping behavior in adulthood-A rat model. Epidemiological studies indicate that early life stress constitutes a risk factor for developing mood and anxiety disorders in adulthood. While most sfudies focus on preweaning exposure, this study examined the consequences of stress during the post-wb,aning period Exp6riment examined e effects of mild juvenile stress (da3Ys 27-29) on eop!ng with stress in adulthood (Day. 56) measuring exploratory_ behavior and avoidance lear/ring. Experiment 2 evaluated the duration and magnitude ofjuvenile stress (28 days) effects on, anxiety indices in adulthood. Experiment 3 sought after a critical-developmental window' during the post-weaning period, i.e. rats underwent mild stress at ither 27-2-9 days (juvenile) or 33-35 days (preadolescence) and their exploring and avoidance learning were assessed in adulthood. Vasoactive intestinal peptide (VIP), a brain extracellular signaling molecule, has tieen implicated in neur0protection, letming and memory as well as in sexual bhavior in genetically manipulated animals. Activity-dependent neuroprotective protein (ADNP), a homeobox-profile containing gene, was recently identified as a VIPresponsive gene (J Neurochem. I999 72(3):1283-93. J Biol Chitin. 2001 276, 708). The current' study was set out to investigate the role of ADNP in brairi function using homologous recombination. ADNP knockout em_b_.ryos die in uteri (Brain Res Dev Brain Res. 2003 144,83), while ADNP+/-heterozygous mice that show a 50% reduction in brain ADNP mRNA expression, exhibit growth restriction (7-20%) and learning deficits. Learning deficits ha the Morris water maze were observed at one month of age and were enhanced at two months of age in the ADNP+/heterozygous males. Assessment of motor activity did not reveal a difference up to 2 month of age. The learning deficits may stem from defective brain development during embryogenesis coupled to deficits in ADNP m adulthood.

Learning Deficits and Neuronal Degeneration in
Cresyl Violet stainiiag revealed degenerative neurons in th.e hippocampus and th cortex of 9-12 months old ADNP+/mce and these results were corroborated by staining with a polyclonal antibody against the C-terminus of the beta-APP (beta amvloid precursor protein). Further studies identified hyper ta phoighospho.ry_lation m the ADNP+/mice In conclusion, ADNP is identified here as a new key gene essential for normal brain function.
Supported by: ISF, BSF. The Lily and Avraharn Gildor Chirfo_r the Investigation of Growth Factors. The Insatute for the Stud), of Aging, Allon Therapeutics, Inc.